Cartax is a supporting character and a recurring item in The Amazing World of Gumball. In many episodes, Cartax usually serves as the Wattersons' family vehicle, and often gets damaged or destroyed in various shenanigans, but always recovers in the next appearance. In "The Routine," it is revealed that Cartax is sentient and can communicate with Richard, albeit in whinnies as though it is a horse.
Cartax is an old station wagon, somewhat resembling a 1977 Ford Pinto (and most 1970 station wagons in general) albeit more geometric in design. Cartax's interior is beige and can seat up to five occupants.
Not much is known about the extent of Cartax's abilities, but it is shown in "The Bumpkin" and less conspicuously in other episodes that Cartax is incredibly durable, having rammed and been rammed by other cars with no apparent damage, smashed through brick walls, fell from heights as high as the top of an office building, and even managing to transport the family underwater, though the car was flooded afterward.
- "The Responsible": It is seen in the front of the Wattersons' house.
- "The End": Richard attempts to drive his kids to Food 'n' Stuff, but they end up walking.
- "The Painting": It briefly appears after Nicole cleans it.
- "The Prank": Gumball and Darwin hide behind it when pranking Richard.
- "The Party": Richard drives Gumball and Tina to Rachel's party.
- "The Club": The Wattersons and the reject club are in it.
- "The Ape": The Wattersons chase down Miss Simian's car with it.
- "The Car": It is smashed by the Robinsons.
- "The Fight": Nicole drives her son to the junkyard.
- "The Fridge": Nicole drives Gumball to the desert.
- "The Phone": Gumball and Darwin hide behind it.
- "The Job": Nicole, Gumball, Darwin, Anais, and Larry chase Richard.
- "Halloween": Nicole drives to the haunted house to pick up Gumball, Darwin and Anais.
- "The Treasure": It appears in Richard's flashback.
- "Christmas": The Wattersons run over Santa in it.
- "The Bumpkin": Richard drives it through multiple locations.
- "The Flakers": Nicole drives it on the way back.
- "The Authority": Richard drives Gumball, Darwin, and Anais to get milk, and gets chased down by Nicole and Granny Jojo.
- "The Virus": It makes a brief appearance being taken over by the virus.
- "The Hero": Richard drives to the junkyard to save his kids.
- "The Dream": It makes a cameo in Darwin's underwater dream.
- "The Game": Nicole drives it from the backseat.
- "The Limit": Nicole forces her family to wait inside the car numerous times.
- "The Finale": It first appears in flashbacks from "The Bumpkin" and "The End," and later makes a cameo near Chunky Bite.
- "The Fan": It briefly appears in a flashback from Sarah's stalker video.
- "The Coach": Richard can be seen driving his kids (whose mouths are wide open) to their house.
- "The Name": Nicole drives the Wattersons to the city hall.
- "The Gripes": Richard drives Anais home.
- "The Vacation": The Wattersons go on a road trip.
- "The Allergy": Richard drives his three kids home, and later he and Nicole attempt to drive to the desert, but fail when Darwin sneezes both of them out of the car.
- "The Password": Richard races Gumball and Darwin to Ripley 2000 on it against Nicole on the minivan.
- "The Pizza": The Wattersons attempt to drive it, but it breaks down and its pieces get stolen by Elmore citizens.
- "The Oracle": Gumball, Darwin, Anais, and Nicole go to the mall in it.
- "The Nobody": Gumball and Darwin watch, Nicole, Richard, and Anais leave in it.
- "The Egg": The Wattersons and the Parhams attempt to drive it.
- "The Money": Richard crashes it through the gas station store on the way to the car dealer.
- "The Return": Richard drives it when trying to rescue his kids.
- "The Signature": Richard drive the Wattersons to the City Hall.
- "The Parking": Its first major role. The Wattersons attempt to find a parking spot.
- "The Routine": Its second major role, revealing its name and as the vehicle for Richard's quest, along with narrating most of the episode.
- "The Comic": Nicole forces the shadow person to fix it.
- "The Wicked": It gets hijacked by Mrs. Robinson, who rampages through the mall.
- "The Origins": Nicole drives Gumball back from the mall, and is later seen again at the parking lot when Richard returns to it after failing to purchase another fish.
- "The Origins: Part Two": Richard drives Gumball and Nicole to the mall.
- "The Girlfriend": Richard leaves the school in it.
- "The Signal": Richard drives Gumball and Darwin to get ice cream.
- "The Night": Anais gets dragged along outside the car as a doll.
- "The Misunderstandings": Richard drives past the house and then reverses into a lamppost after thinking that Gumball is trying to direct him. Richard later drives it to the mall under Gumball's instruction.
- "The Roots": Nicole drives the Wattersons to the mall and later to the lake and back.
- "The Blame": It appears parked outside the school. It is later parked outside the house.
- "The Detective": Richard rams into the garbage truck driven by the dolphin man.
- "The Fury": Nicole drives Gumball, Darwin and Anais to school, and later Yuki damages it by kicking it repeatedly.
- "The Compilation": Footage of Richard crashing through the gas station store in "The Money" is played.
- "The Disaster": Nicole drives the Wattersons to the mall and it gets destroyed in the parking lot.
- "The Rerun": Nicole drives the Wattersons to the mall and it gets destroyed in the parking lot again. It later makes an appearance after the rewind at the end, showing the Wattersons on it driving through the parking lot.
- "The Code": It is shown in a drawing made by Gumball.
- "The Copycats": When Richard is driving it, the Wattersons see Chi Chi, Ribbit, and their parents and bash into a booth, making the milk guy leak. It is seen again when Nicole drives Richard, Gumball and Darwin to get Richard's kidney donated, while Nicole drives it on its side while reading a newspaper.
- "The Fuss": Richard drives off to the Tattoo Parlor.
- "The Outside": Nicole drives the Wattersons to Frankie's place.
- "The Box": Nicole and Richard drive it.
- "The Cycle": Richard drives it to the mall.
- "The Grades": Nicole drives Gumball to kindergarten.
- "The Diet": Richard tries to drive it.
- "The Menu": Richard drives it to eat burgers in every Joyful Burger.
- "The Heist": Richard drives it to the Bank of Elmore.
- ”The Nuisance”: It is seen transforming with the Wattersons when they become model citizens.
- "The Rival": Richard drives it to the hospital. It reappears at the end of the episode.
- "The Vegging": It is stuck along with Anais, Nicole, and Richard.
- "The Candidate": Nicole and Richard drive their kids to Elmore Junior High in it.
- "The Brain": Richard drives it when he mistakes the toll for a drive-through.
- "The Parents": Nicole drives it.
- "The Founder": Nicole drives to Chanax Inc.
- "The Ad": Nicole drives it.
- "The Possession": Richard drives it to the Reuse & Recycling Center and back.
- "The Master": It can be seen wrecked in the Wattersons' living room.
- "The Heart": In a flashback, Mr. Robinson damages it and frames Gumball and Darwin.
- In Season 1, Cartax is a generic representation of 1970s–1990s American station wagons.
- The front emblem is similar to the Pontiac "Arrowhead" emblem.
- The rear end is loosely based on the 1974–1976 Oldsmobile Custom Cruiser, with "GUMBALL" badging in place of the Oldsmobile badging.
- It carries the front license plate "ODH 22," however the rear license plate is covered in mirrored graffiti (reads "T277B" when non-mirrored).
- In "The Club," it is seen in an earlier design without a trunk lid, no window stickers, a slightly different taillight shape, and a non-mirrored rear license plate with a thinner frame.
- Cartax receives a redesign in Season 2, and resembles the 1978–1983 Ford Fairmont Squire.
- The front and rear ends however, are based on the 1977–1978 Ford Pinto Squire.
- The rear license plate is no longer covered in graffiti, and reads "ODH 22" like the front license plate.
- Cartax's name was revealed in "The Routine," and is a play on "Car" and "Artax," the horse from The NeverEnding Story.
- Cartax is mainly driven by Richard.
- Other than Cartax, the Wattersons also own a minivan which resembles the 1984–1986 Dodge Caravan. It serves as the secondary transportation vehicle of the family, mainly driven by Nicole.