Carl is seen as a trouble maker in Season 1, after almost facing expulsion. In Season 2, his love for selling drugs starts when his grandmother Peg convinced him to get prescription drugs to make meth. We don't see a lot of the bad side of Carl in Season 3, but he does end up shaving his head due to Frank convincing him he has cancer. We see Carl's first love interest, Bonnie, who lives in a van with the rest of her family, but their relationship ends when Bonnie's family leaves.
Carl's interests include drinking, weapons, explosives, and death. Deep down, Carl is actually a good kid messed up by a completely dysfunctional childhood. He cares deeply about his family, especially his siblings and his father Frank, despite Frank's complete and utter failure as a parent and role model. In his adolescence, he detaches from Frank though he continues to love the latter and show concern for him at times even when angry with him.
In Season 5, he uses his nephew, "Chuckie", to deliver drugs but gets caught when Sammi notifies the police. In his trial, Fiona wants Carl to grovel, but he instead insults the judge and doesn't name his drug dealer, which lands him a year in juvenile prison. He didn't mind as he wanted the experience to boost his reputation.
After his release from juvie in Season 6, he adopts a thuggish attitude and believes he is too cool for most things. His new way annoyed his family and friends who told him to stop but he ignored. He also tries to impress his new love interest Dominique Winslow though his ways cause her to rebuff his advances. Once his juvie friend Nick kills someone, Carl is then traumatized by the event and throws away his thug behavior, becoming more like old self though silent. Because of this, Carl ends up gaining the affection of Dominique and forms a relationship with her.
Following Dominique cheating on him, he bonded with her father and decide to better himself by joining military school. Carl became even more serious in his return from school, as seen when he cooked for his family and was respectful to his grandfather Bill Darrgen while taking his suggestion more.
Throughout the Seasons
Carl mostly plays a minor role, as he is shown to be a bit of a delinquent and he frequently gets into trouble at school and possibly faces expulsion.
During Killer Carl, he protects his brother Lip from an angry jock who attempted to harm him. Carl struck the bully with a baseball bat and was praised for it.
In It's Time to Kill the Turtle, Carl is excited when Frank gets sober and bonds with his family and friends to pass the time and has fun doing so. Carl is very pleased when Frank does work around the house by cooking and telling stories. However, Lip advised Carl, Fiona, and Debbie to "enjoy the moment while it lasts." Carl doesn't understand Lip's reason and continues to enjoy the sober Frank. Eventually, Frank's soberness becomes too much for the elder children when he tries to break a supporting wall with Carl. He loses his chance at getting the money when Lip and Fiona, spurred by Debbie, force him to drink alcohol. Carl is disappointed since he was enjoying time with his father and doing activities/ When Steve returns to the house, he sees a drunken Frank sitting in his chair holding Liam watching a TV show about politics while the children are pleased.
In Nana Gallagher Had an Affair, Carl watches as Monica takes over as a caretaker for the kids and scrambles at the stress of doing so but is happy to have her. He tries a stunt and builds a ramp, which he rides his bike on and ends up injuring his arm in the process. Carl tells his father who uses this to his advantage by having Carl get struck by a disability investigator and making him think he injured Carl who asks if he can go to the hospital, which Frank promises if he makes it convincing. At the Alibi, he is with Fiona, Lip, and Debbie, as they find their father, he high fives his father over their success. Fiona and Lip inform Frank that Carl got his arm treated and Frank is Liam's biological father. He soon watches as Frank tries to shoo them away. When Frank looks to him for help after he is criticized and punched, he shakes his head and leaves with them. At dinner, when Lip reveals that that Ian is not Frank's son, Carl is surprised and watches as Ian goes over the test and it reveals that he is the child of one of Frank's brothers, making him both the half-brother and cousin of the family. Carl is surprised that he has uncles while Fiona states he has three.
Carl continues most of his habits and is tended to by his siblings.
In Can I Have a Mother, Carl along with Debbie meets their grandmother, Peg who comes to visit. Carl is impressed by her having a gun and is pleased to keep her secret after being given money. He later wheelchairs her to the Alibi to find his father and she promises him a drink after refusing to pay him again. At the end, he is sleeping in the old van in the backyard with Frank who was kicked out by Sheila and had his old room taken by Peggy. Carl wakes his father up to tell him that Frank wet the bed, a dismayed Frank told him to scoot over to the dry area.
During A Bottle of Jean Nate, Carl ends up striking a relationship with Peg and has fun with her teaching him to play poker, buys him things from department store, even wants to help him learn a skill... making meth. Frank knew Peg had ulterior motives other than just visiting him and his family, as Peg takes Carl with her to the local drug store to ask people going in if they could buy certain medications for his sick grandma, a young boy being a perfect cover. Despite this, a woman knew what he was obviously doing but complied after he promised her a gram when they are up and running. They get the items they need and head back to the Gallagher house and set up in the basement with their meth making operation. Peg needs to leave and asks Carl to keep an eye on the cooking. He ends up causing an explosion, rocking the entire house. This causes Fiona to keep him away from Peggy.
In Parenthood, Carl is upset about being separated from his grandmother as Fiona scolds him for his act on the house.
Carl is the only Gallagher child loyal to Frank after Debbie sees his ways.
Carl has his head shaved by Frank, who convinced him he had cancer because he wanted to extort the Make a Wish Foundation. Instead, the Foundation sends Carl to cancer camp. Before leaving, Frank gives Carl an unmarked bottle of antacids and tells him they're pills to cure his cancer. Carl hates the camp, as everyone is treated with "kid gloves" and made to participate in wholesome activities. He gets to know another kid and decides to defy the rules set by the camp. A pretty female counselor notices that Carl is unhappy and tries to help him have more fun, but her activities don't live up to Carl's expectations. At night, Carl tries to break into a cabinet with a new friend and another female camper, when the female counselor catches them in the act. Upset that she has failed in her duties as a counselor, she begins crying and asks Carl and his friend how she can make their camp experience more fun. In response, Carl tells her he wants to see real life boobs before he dies (still believing he has cancer). The counselor complies and shows Carl and his friends her breasts, but is caught by the other counselors, and ultimately fired.
Carl also has an unhealthy fixation with death, and goes so far as the attempt to kill his cousin Patrick using rat poison in the middle of the third season (after Patrick tries to evict them from the family home). Fortunately, he survives, and Carl's biggest offense is attempted murder, rather than first-degree murder.
Since Carl is still a kid, he has no understanding of sex and sexuality, but has a strange fascination with homosexuality and what exactly it entails. Often in the third season he asks members of his family, and his friend Little Hank about gay sex, simply out of curiosity. Ironically, he and Liam are later placed in a foster home with two gay men interested in adopting them. While staying at the foster home, Carl discovers the couple's gay porn collection and is caught watching it in the couple's bedroom, to which he asks "why do they all have mustaches?'
Carl eventually returns back to the Gallagher home later in season three after Fiona is granted full guardianship of the kids.
Later, in Order Room Service, he attempts to bond with his father Frank, after Frank tells Carl of time when Carl's grandfather and Frank did a heist. They use the security code he was given to break into his "Foster Gays" house with Frank and rob the place. The two celebrate their loot and bask in the glory. After Mickey's wedding, Lip and Ian come home to find a police officer arresting Carl for the crime. Lip tries to defend Carl from the officers but Frank appears on the scene. In a shocking stray from character, he confesses to being the one who committed the crime, by telling them he forced Carl to give him the code and shows items to prove it forcing the police to let Carl go. Carl is tended to by Lip as Frank is arrested, as Carl was amazed by his father's act and watches as he is taken away bidding them goodbye.
After Frank is released but placed in the hospital for his liver, Carl tends to him and shaves his head after it is hinted that Frank may have cancer.
In My Oldest Daughter, when Frank's liver fails, Carl takes it on himself to get him pain medication and find him an organ donor. Carl later begs Fiona or Lip to help their father but they don't want to give their liver to Frank, to his sadness. At night, Carl pleads to Fiona who refuses again and apologizes to Carl as he leaves, while Frank tells him and Fiona that he will go to his eldest daughter Samantha for help.
During Like Father, Like Daughter, Carl is going through puberty and flirts with Debbie's new friends who are flattered. He soon helps Frank find Samantha now a grown adult with a kid of her own Chuckie Slott, making Carl remark that he's an uncle. Carl also remarks on his new sister looking like a female Frank and lets Frank go off to talk with her.
As of There's the Rub, Carl breaks his sleeping father's leg at his request to get a check for the liver surgery. Later on, he is syphoning gas from a school bus before he meets with his father and he formally introduces him to Samantha who is excited at meeting part of her extended family and introduces her son to him. Carl is less than pleased to have another older sister but goes along with his father's plan of building a lodge.
Very soon in Iron City, Carl calls Mike Pratt to have him bail out Fiona after she is arrested. He also helps in the search for Frank since he is needed to reclaim Liam or else he'd go into foster care. Carl goes home where he helps Sammi tend to Frank and soon informs the arriving Lip of the new additions to the family, after he inquired on who they are while looking for Frank. He is present with the rest of the family when Liam is released from the hospital. At the end, Carl burns down the sweat lodge his father was in after he is told it nearly killed him.
During A Jailbird, Invalid, Martyr, Cutter, Retard, And Parasitic Twin, Carl is present when Lip takes charge in the house and he agrees with his brother on Sammi needing to earn a keep if she intends to live in the house. Carl also beats up bullies for insulting his little brother's condition. He is also worried about his brother's condition but relieved to see that he is fine.
During Hope Springs Eternal, he is less than pleased when Fiona throws away his taser for her parole officer meeting. He and Debbie decide to go to Sheila's house where they help Sammi tend to Frank. Since Carl also needs a parent to attend his meeting and since Fiona can't go, he decides to take Frank. Carl also helps his half-sister scam people to get money for Frank and is successful in the scheme. He is later present at Lip's college and amazed by the party, as well as Amanda performing sexual acts on Lip. In his school meeting, he takes Sammi along with their father to speak. He watches Frank stick up for him and justifies his attack since he was probably doing them a favor, since they'll most likely be successful. Carl is pleased that his father's rants actually came in handy and he is let off the hook.
In The Legend of Bonnie & Carl, he meets a girl named Bonnie, who lives with her family in a van. They scheme together to gather money for Bonnie's family, and Carl slowly falls for her. He denies this however, when she asks him about it, to which she replies she doesn't want him to love her. Carl goes to the hospital and watches as Sheila marries his comatose father. He prepares to part with his father but is shocked Frank is suddenly rushed out the room, as the doctors explain he is getting a liver transplant since an opening appeared, to Carl's relief.
During Emily, he continues seeing Bonnie and lets her move in along with the family, with Lip giving permission since he wants to scare his girlfriend's parents and they are paid a large sum of money. The next day, Carl goes to see Frank at the hospital and is confused by his father's delirium from his new liver.
After Frank's surgery in Lazarus, Carl goes to see Emily but the van is gone, and so is Bonnie, to Carl's sadness. Carl moves past it and heads to visit his father, where watches Sheila and Sammi fighting over who should visit Frank. He sneaks in the hospital room, while they are distracted by security and talks with his father, happy to see him okay. Carl then leaves the hospital with Frank who got a new liver. Wheeling Frank out along the Chicago waterfront, he watches as his father takes out a can of beer and victoriously rejoices about surviving and still being able to drink. Frank then shares the beer with Carl to thank him for his help in his time of need. Father and son soon hug at Frank's recovery.
The Gallaghers find out Ian is bipolar. Carl teams up with a gang of drug dealers and spends his time dealing small amounts of drugs for money.
Carl is eventually given the task of transferring some heroin to Michigan, and seeks advice from Frank about how to do so. Frank warns Carl that he may be easier caught than someone like Chuckie. Carl agrees, and Frank gives him the money to cover the bus fare to Michigan. Carl, having earlier convinced Chuckie to do things for him in exchange for protecting him at school, takes advantage of his nephew's naiveté and straps pounds of heroin to his body using duct tape. Chuckie isn't fully aware the bags contain drugs, and agrees to accompany Carl on his trip to Michigan. The pair arrives at the bus station and as Chuckie sits down, Carl spots a security guard with a detection dog and leaves Chuckie behind. The dog begins to bark and Chuckie is caught and arrested.
Sammi later shows up at the Gallagher household and accuses Carl of forcing Chuckie to assist him. Carl repeatedly denies her accusations and eventually, the police show up. Carl's siblings tell him to run, to which he bolts out the back door and down the street before getting caught by the police.
Back at the house, Sammi admits she told the police it was Carl, and she also told Chuckie to tell the police that Carl made him do it. Carl is held at the police station several hours for questioning. The next day, Sammi confronts Carl while he is being held and threatens him, to which he replies, "Bring it, bitch." Sammi attacks Carl and punches him repeatedly. In court, Chuckie is sentenced 120 days in juvenile prison, or 60 on good behavior. When asked if Carl regrets his decisions, he simply admits he only regrets trusting Chuckie with the job. The judge is appalled and tells him he will end up in juvie, and follows by asking if that's what he wants. Carl replies, "Yes, please" and humiliates the judge with a vulgar comment. She sentences him to the maximum time of one year in juvenile prison.
Carl arrogantly tells his siblings he intends on making juvie his bitch and is taken away. The finale concludes with Carl and Chuckie on the verge of a gang war.
Carl is released from juvie a few months earlier than expected on good behavior. On his way home he befriended an older boy named Nick, who had been in juvie since he was a child but was released due to his eighteenth birthday. Carl allows Nick to stay at the Gallagher house, much to Fiona's dismay. Carl returns to school and brings Nick along with him. The two smuggle a backpack filled with a cache of weapons into the school and begin running a business selling them. Teachers quickly catch on including the school principal and a math teacher who approach Carl and to his surprise, ask to purchase guns of their own. Carl also takes interest in a classmate, Dominique Winslow.
Carl is not pleased when Chuckie is also released and promises to hurt him, though he never acts on his threat and sees his nephew as foolish in his views.
Carl's attempt to impress Dominique especially when her cop father chases him away. He and Nick soon find a bike which they buy for Nick, as the latter tells Carl how he had a similar bike when he was younger but his father traded it for crack. This also causes Carl to get a bike for Dominique to get around easier, somewhat flattering her.
When the Gallaghers are briefly kicked out of their house, Nick's bike is soon stolen and Carl stops him from going after the person out of disrespect. Carl briefly lifts his spirits by getting him a car. Later Carl, Nick and Debbie are in the car driving to Debbie's baby's gender party, they see a kid on his bike. Nick attempts to reclaim his bike but Carl tells him that it's not worth it. When Nick leaves the party unexpectedly, Carl realizes where he went and follows him. He finds Nick sitting on the kid's porch with a bloody hammer, pondering on his thoughts as crying is heard. Carl walks up to the porch and questions what he did and sees the dead body of the kid with his grieving mother and pukes at the sight in horror. Nick tells Carl he should leave because he called the cops, as Carl questions why he did so but Nick only gives him a look of regret. Carl hears sirens approach. Though reluctant, Carl leaves and watches his friend being taken away. After Nick is taken to prison, Carl decides he no longer wants to be in the drug business. Carl later digs up money and gives it to Fiona and firmly tells his sister to buy back their house with it. Carl is at the house when Fiona reclaims it and is proud.
He is pistol whipped by one of G-Dog's men, when he attempts to stay out of a deal. He goes to Veronica to get stitches, and reluctantly ends up telling her what happened. When Fiona finds out, he tells her about how Nick killed the boy and how 'he doesn't want to see that'. Carl goes to Frank for help and the latter fills in for Carl in his business and ends up drawing their attention from Carl. Meanwhile, Carl and Sean later confront G-Dog and his men, resulting in the last of Carl's drug days who take their possessions as compensation for his leaving. Carl is given a job at Sean's diner where he washes dishes and earns money in a working way.
He distances himself from Dominique who was used to his attention and he ignores her. When Dominique comes to him for help, he accepts before he is shocked to hear that it was a ploy and she actually likes him. Carl loses his virginity to Dominique, once she comes onto him. Dominique also congratulates him on his job and for being real with her. Things started looking better for him, as he continues to stay away from the drug business and gets a new girlfriend.
He later joins his family and friends in throwing Frank off a bridge after he ruins Fiona's wedding.
As seen in Hiraeth, Carl still dates Dominique, but they do not have a good sex life, as Dominique refuses to perform oral sex on Carl, due to his being uncircumcised. Carl returns home where he, Lip, and Ian are not surprised to see the unconscious Frank who survived the fall. They leave him where he was and Carl asks his brothers if they are circumcised, to which they say yes. Carl checks Liam's penis and sees that even he is circumcised. He makes it a problem and confronts Frank and learns he is circumcised too. Carl bluntly tells his father that everyone kinda hoped he was dead after he didn't show for a month. Like his siblings, he wants nothing to do with him but still has some care for him.
During Swipe, Fuck, Leave, Carl goes to the doctor and gets himself circumcised but it is a painful process for him. He struggles with not getting aroused by his girlfriend who teases him to test his words and it causes him to break a stitch. He gets the problem fixed and the doctor gives him a way to overcome it. He returns home and rests as Fiona comes in asking about his pain and he tells her that he's alright. When she tells she's going upstairs, he told her she can't as he previously found the walls were blocked with cement, courtesy of Frank getting revenge on his children for trying to kill him and kicking him out. Carl was not pleased by his father's act and worked to destroy it. When Lip and Ian teased him for his circumcision, he has them stop after he telling him that it already hurt without them making him feel less like a Gallagher. His brothers later give him painkillers, as an apology. After his recovery, Carl sleeps with Dom again.
In Home Sweet Homeless Shelter, Dominique gets Gonorrhea and her father Luther Winslow angrily blames Carl but he escapes him. Carl gets a test done to see if he has the disease but sees that he tested negative, meaning he couldn't have gave it to her. Carl finds out from his brothers that Dominique might have contracted the STD with someone else, causing him to suspect her. He follows her and encounters his father along the way, sharing a glare with him. Carl later sees Dominique kissing another man, at a college dorm. He is heartbroken and takes a picture of the act and reclaims the bike he brought her, out of spite. Carl goes to her house and shows the test and the picture to Dominique's father Luther who is shocked by it. To get even, Carl happily tells him her location so that her father could punish her. Afterward, he watches as police storm the dorm and is happy at the sight. Afterwards, he is with his family as Fiona tells everyone they must earn their keep to live in the house. Carl is displeased since his money paid for the house, while Fiona tells him that the house is in her name. Carl is further displeased to see Frank has opened a homeless shelter in an old house and turns his children away for their actions.
As of I Am a Storm, Carl grows a bond with Dominique's father who helps him get into military school by getting a minority scholarship. He is confident in passing the test, since his brother is part black but fails the test. He does another a test, which shows he is part Apache, and Dominique's father is descended from Puritans.
During Own Your Shit , he is jealous to see that Frank's homeless shelter has received new items and remarks to Fiona about their failing house. He is also having second thoughts about school. He later talks with Dominique and she apologizes to him for how their relationship went bad. Carl considered to get back with her and told her father that he changed his mind and he decided to get back with Dominique but Luther shows him of how she is still up to no good. Carl meets Dominique's new boyfriend who insults Carl for getting circumcised and she states that the issue doesn't bother her anymore, which causes him to feel betrayed. Carl gets back at both of them by revealing her STD, leaving her boyfriend horrified with her as a smiling Carl walks off.
Soon in The Defenestration of Frank, Carl is preparing for school and is displeased to see Frank return home. Carl insults his father but is angry when Frank tells him about his new luxurious items in his shelter and takes Liam to enjoy them while insulting Carl. The next night, Carl goes to military school and is seen off by most of his family and Luther.
As seen in Requiem For a Slut, Carl does great in the school, as it changes who he is and is more caring and he tries to do stuff with honor. Carl's personality is different due to military school and it shows that he can turn his life around. Before long, Carl receives word of his mother's death and decides to go to the funeral, Carl returns home and is greeted with welcome arms. Carl, Debbie, and Liam help their father gather the meth Monica left for them. That night, Carl meets his maternal grandfather Bill Darrgen for the first time and watches as he fights Frank, before Lip tells him who he is. When Bill takes notice of his uniform, Carl explains that he hasn't chosen a branch and is accepting of the latter's compliment to his activities in school and recommends he joined the navy like he did. After his mother's funeral, he and his father go to an alley where Carl graffiti's a wall in honor of Monica. He is shown to have made amends with his father, as they share a beer and pay their respects together before leaving.
After his mother's funeral, Carl has return from military school for the summer. He later finds out his scholarship was given away and he needs to find a new way to pay his tuition.
In Where's My Meth?, he is left with some meth that he sells for more money and buys a hot tub. He is surprised when Frank shows up and tells him he has decided to change his ways and apologizes to Carl for what he has done to him though can't remember anything. Later, he and Ian are spotted at the unit by a man named Eric Stark who owned some of the meth, forcing the brothers to run.
During God Bless Her Rotting Soul, Eric tracks them and Carl is attacked by him when the thug nearly drowns him in the hot tub as Ian rushes to his aid but is subdued and Eric threatens the family for his money. Carl and his brother research Eric, as he and Ian learn of his dangerous past and decide to ask Lip and Debbie for help but they are unable to get enough money. to Fiona for help. While the others apologize for not listening to her, Carl doesn't do so and tells her to stop gloating and help out before Eric comes for her too. After Liam and Frank (who had decided to change and experienced guilt) appear to help, Carl and his family are forced to dig up Monica, since Fiona put her share of meth in the ground with her. After digging his mother up, Carl finally admits Fiona was right before they get what's needed. They arrive at the storage unit and pay Eric, Carl offers his hot tub as a way to get more money but its still not enough and Eric threatens them. Fortunately, Frank steps in and Carl watches as he successfully intimidates Eric to accept the payment or be faced with death if he comes near the family again as Carl is surprised by his father's actions and leaves the area with his family. Eric then claims the tub that Carl offered and the boy is disappointed by it and several women leaving him.
In Fuck Paying It Forward, Carl and Ian go for a run before they are told of a burglary. Carl gets involved since he heard a veteran was the victim, he promises the veteran that he will catch him. He is shown to still be put off by Frank's change, asking if he's continuing as "Father Frank" but the latter corrects him by stating its "Saint Francis". Carl and Debbie watch as he bonds with Liam before they leave, he and Debbie agree that Frank is still himself though humor him, since he is showing signs of improvement. At the end, Carl watches as his niece walks to Frank and is happy at this sight and by his father. He soon catches a burglar and chains him in the basement.
Afterwards, Carl starts working odd jobs including working for a knockoff Uber company to earn money. Carl soon handles a robber who was also a drug addict and succeeds in detoxing him. With this he holds several of them in the basement for days, in hopes that he will get them clean in return for money from their families. It works a couple times but then it starts having problems. He takes in young girl named Kassidi and she points out that none of the families of the group he has taken will given him money. He gets really bummed but she tells him she has a plan. She convinces him to send a ransom note to her wealthy father and that way he can get his money. Her father, who knows it's a scam, gives Carl the money hoping that she will come back home. Carl lets her go now that he has the money he needs, but she doesn't want to leave and begs Carl to let her stay with him. She then gives him oral sex and he allows her to stay. Carl and Kassidi start dating and fall in love fast. Kassidi is wild and carefree, similar to Monica. When Carl doesn't hold her hand, Kassidi gets upset though they reconcile after he does the act. After he gets ready for military school, Kassidi doesn't want him to leave but Carl tries to convince her that long distance will work but she is still upset.
To try and show her that he is committed, he buys Kassidi a ring off of a pimp to give her as a promise ring. Carl sets the basement up romantically with candles and leads her down to there he tells her he wants it to be special and so he wanted to take her to the spot where they fell in love. He then pulls out the ring and Kassidi thinks he is proposing and she says "Yes, I'll marry you." A shocked Carl says "Marry me?" and she says yes again. Carl didn't want to upset her and thinks he does love her so he initially believes marriage is okay. Kassidi then wants to get married right away and Carl, who doesn't want her to lose her mind, agrees. They are then married and everyone in his family except Frank disagrees with Carl's decision, but doesn't make any intervention.
In order to stop Carl from going to military school, Kassidi handcuffs him to his bed for a day until he falls asleep. Carl then wakes up uncuffed (courtesy of a sleepwalking Liam), finally realizing that military school is more important than Kassidi, he soon sneaks out in order to buy military clothes in preparation for school.
Carl then makes his way onto the bus leaving for military school with Kassidi on the other side of the bus yelling and crying to Carl, begging him to come back. Carl ignores his wife's pleas and departs the city.
In the months that followed in Are You There Shim? It's me, Ian, Carl excelled in military school reaching the rank of Corporal and is more serious. Carl only has one problem being his wife Kassidi who has followed Carl to military school and set up camp outside the fence of the school and has decided to support her husband in his endeavors by dressing up as a cheerleader and cheering for him, to his embarrassment. Carl has gotten over her and is dismayed Kassidi still shows signs of her clinginess to him by counting down the days until he is let out of school and professing her love of him. Carl also learns until she is taken care of, he won't be able to advance to a new rank. When complaining about this to his platoon, one of them who Carl was having problems with decided to help. The cadet later told Carl that he handled it and the body won't be found, implying he killed Kassidi or abducted her to keep her quiet. There was no trace of her at the camp as Carl became worried at the fate of his wife. He later returns home and finds things amiss.
To really advance his military future in Mo White!, Carl gets decides to do community service and get a recommendation. He decides to euthanize dogs but is horrified by the procedure and gets them out for a peaceful death.
Carl later goes to a congressman for help but he has given a recommendation to someone else though with V's help he does get it.
Unfortunately in the next episode, the boy who previously had the recommendation confronts him and challenges him to a duel. Carl goes to a former mercenary for help and becomes scared of the details of a duel but gets enough strength to do so. Carl meets the boy who ends up shooting himself in the leg, to Carl's shock. Carl learns the boy actually wants to be a poet but his strict father wouldn't let him and wanted him to be a soldier. The boy says with his wound, he wouldn't have to go now but Carl says its a flesh wound and it will heal. Hearing this, the boy begs Carl to really shoot him in his other leg, successfully doing so by annoying him with his poetry. Carl is put off by the boy's gratitude but proud of pulling the trigger and leaves as the wounded boy wishes him luck at West Point.
Carl attends a ball for military school and things are good as he meets a girl Kelly Keefe (the daughter of the officer throwing it) who comes onto him and they nearly have sex but she passes out. After Kelly wakes up, she accuses him of filming the encounter before chasing him and he hides in her father's study. Her father is there and Carl tells him what occurred but he is promptly kicked out. Carl returns home and complains about his venture as Debbie does about her own. However, they stop when Liam's classmate Sissy decides to move in with him after telling him, she's supposedly pregnant with his child. Carl and Debbie are confused by this display before they intervened by telling Liam that he didn't impregnate Sissy, due to the timing. Carl tells Liam to play along until they have a plan. Carl goes outside and buries a dead dog before he finds Kelly present, she returns his phone that he left behind and sees he didn't film her but his ex-girlfriend Kassidi. Carl tells Kelly he didn't do anything to her, as she apologizes for her misunderstanding and kisses him. Carl is present at Ian's hearing and is pleased when he pleas not guilty on counts of insanity. Later on, he and Debbie have Lip who was told of Liam's situation to help and kick Sissy out by drugging her and bringing her to a clinic.
Carl and Kelly later help with teaching Ian some new moves to help him survive prison. Carl is present at seeing his brother off and wishes him luck.
Carl is woken up at two in the morning, he and his siblings investigate the sound in the attic and see its an alarm with a picture of Ian. They realize that he left them a memento and smile at the gesture.
Carl decides to move in Frank's room since he moved out. He agrees to babysit Liam and Franny before Kelly arrives to help with his lessons but he is disappointed she only wanted to study and has Liam help. While going over military assessments, Carl is informed by Debbie of Fiona's hardships with a car accident and learning of Ford's marriage. A surprised Carl curses Ford and worries about his sister. Later on, he and Kelly keep studying and she is exasperated with Carl's lack of knowledge on the subjects though lets it slip that she wanted a boyfriend with her at West Point. Carl is surprised by being her boyfriend and decides to try harder with his childhood helping him excel. He is later present when Fiona decides to move back in and watching Ford's humiliation and Fiona getting revenge on him by shooting a paint gun at his rear end and takes amusement from the act.
In The Apple Doesn't Fall Far From The Alibi, Carl and Kelly are still seeing each other and fooling around in the tent so her father doesn't catch them. Later on, Frank asks Carl for help and asks him to masturbate in a cup while promising him a hundred dollars. Carl accepts and does so, having no idea what Frank will do with it.
During BOOOOOOOOOOOONE!, he decides to take up a more assertive stance in sneaking with Kelly but is caught by her father who puts a gun to his head and orders him to leave. At home, Carl soon learns of his father having kids, he scoffs at this while listing himself as an example of his father's failure and calls his fault a military psychopath. Carl later talks with Kelly towards their future by taking Carl to her home. When Kelly forms her own vision board by telling her father and boyfriend that she still wants to go to school and see Carl. He watches as Kelly also abolishes her father's rules and makes a list of demands to him. After ending her rant, she tells Carl that they will have sex in her room and he sheepishly goes along with this.
In Los Diablos, he continues seeing Kelly and makes good with his coworkers though he is angry at being harassed by his old friends who attempt to mug him.
During The Hobo Games, he is congratulated by Kelly on his job and wishes him luck as she and Debbie hang out. Kelly sends Carl a picture and he worries because of their closeness, after his coworkers comment on it.
In You'll Know Bottom When You Hit It, Carl confronts Kelly on her association and she breaks up with Carl for believing she'd be attracted to Debbie and not trusting her.
As of Lost, Carl gets ready for work but finds his father and though tempted to leave him where he is, he decides to help him. Carl along with Debbie and Kelly learn of Frank's leg injury and carry him inside. Carl spends the day at work and is put off by his boss' flirting before he attacks a robber for shooting at him. After work, he finds Debbie and Kelly sleeping on the couch while bemoaning this before going upstairs. At night, he finds his sister crying on the porch and asks what happened. Debbie explains she took the chance to kiss Kelly but the latter rejected her. Carl sympathizes with her over being dumped by Kelly.They reconcile before they spot Kev dressed up as Jesus carrying a large cross.
During Found, Carl and Debbie go out for revenge on Kelly, while telling Fiona they are going out. The two vandalize Kelly's truck and quickly flee the scene when she nearly spots them. Carl later goes to work where the owner thanks him for his acts of saving the restaurant, offering him a promotion and better pay. Carl considers it and tells Debbie that he is quitting school while she tries to protest this but he refuses to change his perspective. He later goes back to work, where he talks with his manager before he notices Kelly's truck and quickly runs away. However, Kelly storms in and tackles him down as she berates him for being willing to throw his life away. Kelly straps Carl's hands to his back as she takes him, while telling Carl's boss that he quits and will go back to school. Carl is loaded up in Kelly's truck and taken away while his manager watches the scene, she comments on how Carl has a real lady keeping him in line.
- He is one of the few Gallagher children to call Frank "Dad".
- After Lip, he is the second Gallagher to have a juvenile record.
- Carl shares similar traits to his father, though Lip is more like Frank.
- He has attempted to kill two of his relatives cousin Patrick and father Frank but both survived and held grudges against him that were soon forgotten.
- Carl seems to notice that all Gallagher's attract unhinged partners.
- He is the third of the Gallagher children to get married, after his sisters Fiona Gallagher and Samantha Slott.
- Similar to them, his marriage lasted briefly with his spouse's disappearance.