Whenever a character is naked onscreen, their butts and genitals are censored in a cube of pixels, they are never shown.

Several moments of relationships between characters, most notably seen when focusing on characters at Elmore Junior High.

Richard is seen at home in his underwear in some episodes

Some adult jokes are sprinkled throughout the show, some more obvious/risque than others. They would fly over most kids heads.

Gumball and Darwin try performing surgery on another character. Everything goes wrong and their guts and organs go flying everywhere, but since the character is a balloon, the organs are invisible.

Characters gets brutally beat up , occasionally . Not bloody but moderately heavy detail on the bruises and injuries

Sometimes, characters yell at each other, and when they hit each other sometimes appear "red" wounds and black eyes, but nothing very worrying and only for comic effect.

In "The Prank", Richard is shot by a tranquilizer dart, like Nicole in "The Shell" and Darwin in "The Origins: Part Two".

In "The Dream", Darwin said he wanted to eat Gumball; in the same scene appears with Gumball's arm bitten. However, it isn't worrying because after appears normal.

In some episodes characters apparently die for comic effect (Lego-like characters lose arms and the head -but still alive, Sarah the ice cream melts, Anton the sandwich is chewed, Alan the balloon explodes, Banana Joe is trampled, etc.) until the next scene/episode.

Sometimes characters get electrocuted, principally by tasers. In "The Skull", Gumball, Darwin and Clayton use shock therapy to cure their lying. In "The Crew", in the final seconds a group of old people are electrocuted off-screen by a taser. Both scenes were censored in the United States for avoid a TV-PG rating.

In the episode "The Lesson" some of Gumball and Darwin's detention mates fight off screen. When they escape the room, some jelly (which resembles blood due to one of them being a cherry) splatters on the door window. In "The Roots", Richard kicks off his ears and a tooth briefly (no blood).

Slapstick is very frequent, such as a car falling from very high, people in hospitals, destruction of walls and houses and explosions, but in a comical context. In some episodes can be seen some mild fantasy-looking organs like hearts ("Halloween", "The Debt"), brains ("The Genius", "The Goons") or kidneys ("The Gripes"). In "The Traitor", Gumball and Darwin want to do a trasplant in a balloon and all blood and organs are invisible, so they say "there's air everywhere". In "The Ollie", Gumball wants Darwin to split himself (meaning leave quickly) but he literally does that.

In the episode "The Wicked" there's a lot of more fantasy violence than usual, including animals attacking people and a lot of chaos and destruction; Ms. Robinson, who first laughs looking at the havoc, is later constantly injured.

In "The Wand", Gumball and Darwin are out all of them and they are shown as red meat and some bones, and in another moment some parts are mutated (like Gumball and Darwin's face are their butt and their butt are their face).

In the episode "The Fury" there is a mild fight scene between two characters, featuring exaggerated heavy blows.

Vomiting and spitting is present in the show but it's very rare.

Gumball tends to say "what the what!?" multiple times. "Gosh darn it" and "dagnabbit" is said too.

In "The Storm", Gumball says "bimbo", but it was replaced with "coward" in the US airings. If you don't know what bimbo means just think about it as the Mexican bread company

Timmy says "get bent" in "The Internet".

In "The Safety", Gumball steps on Darwin's foot and Darwin yells "OH YOU-", after that a picture of a mother, then a farmer shown bucking hay, a picture of a donkey, then a picture of a clown is shown. It's implied he said "mother forking ass clown", which sounds more like "motherfucking ass clown". Most likely to go around childrens' heads.

One use of "suck" in the Halloween episode, "The Ghouls."

In "The Mustache" Gumball and Darwin become "men" after eating by accident Richard's vitamins. In "The Banana" Mr. Small drinks a herbal tea that very relaxes him.

Some episodes are centered around the fact that Richards father abandoned him as a child and it may be emotional for children who have a parent that isn't around

A character called "Sussie" who is basically a chin character made with a real life chin which is a little bit creepy

The second half of "The Girlfriend" may be scary for younger viewers.

Almost episodes, it might harmless to some viewers

The Live-Action imagery in the show can be surreal for viewers.

Explosions are quite frequent, but never that intense.

Sometimes Gumball yell in the show

Gumball mentions suicide briefly in the episode "The Test".

Not specially a frightening/intense thing, but in the show some black humor is present and discussed (like government and business corruption, social groups, consumer society, despotic behavior, etc.), specially in seasons 3 and 4, that only mature children and adults may understand.

Carrie is a ghost. In "The Ghost", she continuously robs Gumball's body because she is unable to eat in her ghost form. This can be quite scary for very young viewers.

In "The Microwave", Gumball and Darwin make a monster out from a microwave. Some monsters and things might scare someone.

The faces from certain characters in some moments of the series, especially in Season 1, like Anais' resigned face in "The Kiss", can scare to very young viewers. Some scenes can be mildly intense as well.

Some scenes from "The Night" like Larry's sealed mouth and Daisy's dream can be scary for some viewers.

The episodes "The Joy" and "The Parasite" can be scary for some younger viewers.