The Laziest (S01E11)
After Gumball and Darwin keep pestering Larry to beat Richard in a lazy-off, and causing him to lose his job, car, and girlfriend, he reverts to his former self known as Lazy Larry.
The Ghost (S01E12)
Carrie, a ghost, constantly keeps possessing Gumball's body in order to eat.
The Gi (S01E15)
Nicole imagines Gumball and Darwin to grow up fat and lazy.
The Picnic (S01E20)
Banana Joe has had three helpings during the field trip.
The Wand (S01E29)
Gumball drinks the water from the sink to convince Richard that a magic wand can unclog the pipes.
The Microwave (S01E33)
The monster that Gumball and Darwin made is now big and ate Darwin whole with a hose tied on himself. Gumball backs away while he turned on the hose without noticing, The monster became hugely bloated until it bursts.
In the Christmas special in the hospital, Richard wanted to be in the nice list for accidentally running into Santa with his car, he tries to do nice things but backfires, one resulting on a patient inflating until they burst.
The Authority (S02E19)
Gumball, Darwin and Anais gain Richard's characteristics after being sheltered by Granny JoJo's bad parenting techniques.
The Dream (S02E23)
Gumball forces Penny to eat a blueberry muffin, causing her to swell up as she is allergic.
The Internet (S02E37)
Darwin becomes fat for a few seconds from watching a puppy video.
The Kids (S03E01)
Gumball raps about his metabolism, describing his "baby fat".
The Allergy (S03E16)
Darwin inflates during a sneeze.
The Password (S03E09b)
Richard gets fatter when Gumball feeds him a large sandwich.
The Countdown (S03E18)
Gumball and Darwin end up in an alternate timeline where the classmates are fat.
The Advice (S04E23)
Gumball and Darwin accidentally knocked over the oxygen machine need for Tobias, so Gumball tried pumping the machine but it made Tobias inflate.
The Loophole (S05E10)
When Darwin was choking, Bobert use his hand as a hose to inflate Darwin to stop choking.
The Matchmaker (S05E16)
As Terri and Darwin are succumbed to Carrie's love potion and Gumball has learned the truth about Darwin's real crush, Gumball and Carrie try to get them to split up by overfeeding Darwin in his sleep. This plan backfires when the love potion takes effect on Terri again the next day. "That means there's more of you to love!"
The Console (S05E18)
When doing a sidequest for the Crocodile Woman, Gumball gains the appearance of a stereotypical overweight gamer.
The Stars (S05E22)
Gumball and Darwin overeat at Larry's restaurant, and loosen their belts. They immediately lose weight in the next shot.
The Diet (S05E24)
Richard attempts to lose weight by going on several different diets all at once, resulting in him putting on even more weight.
The Menu (S05E27)
In order to learn the name of the secret menu item, Richard has to eat a burger at every Joyful Burger restaurant in Elmore within one hour.