A subtrope of Alternate Universe where the AU is inhabited by cartoon characters. Exists alongside a universe like ours inhabited by flesh and blood human beings. Usually toons and humans are treated as separate species, if they interact. Humans may be fearful of Toons because of their different abilities. Note, however, that to whom, where, and when Toon Physics apply depends on the work, and frequently on the Rule of Funny. Comes in two flavors:
- Type I: Like our world, only with cartoon characters interacting with real live people.
- Type II: An alternate (or parallel) universe exists alongside our world, and it is populated by cartoon characters. There is often travel between this world and one much like our own.
Examples of Type I:
- Who Framed Roger Rabbit
- Looney Tunes: Back in Action
- The Rocky and Bullwinkle Movie
- Bonkers was a cartoon, but some people in the cartoon were people and some were toons. An unusual example where the humans are also animated, just more realistically.
- Last Action Hero. In Jack Slater's movie world, cartoons mix with human beings in the police station.
- Animaniacs, though even the Warners and Slappy Squirel know that their 'real world' is still a cartoon.
- The Sponge Bob Square Pants Movie and The SpongeBob Movie: Sponge Out of Water, where the undersea world is animated and the surface world is live-action.
- The city of Elmore in The Amazing World of Gumball, a place where Everything Talks and can also become a Funny Animal, is often implied to be a unique location on an otherwise mundane Earth: Citizens of Elmore are shown with various forms of animation, the geography of Elmore consists of real life photographs, and in-universe media often shows humans in live-action, something never shown in Elmore itself. The series's creator even cites Who Framed Roger Rabbit as an influence for the show's use of Medium Blending, liking the idea of cartoon characters being in real life. Other episodes blatantly contradict this, making mention of anthropomorphic non-humans being from places far outside of Elmore.
Examples of Type II:
- Cool World: an alternate universe exists, populated by toons (or Doodles as they were called; the humans were called Noids).
- The Fringe episode "Brown Betty" might have featured such an alternate universe, as seen when story-world Nina Sharp communicates with story-world William Bell using the window device (though this may have been a choice to go for a retro-aesthetic).
- Space Jam
- Captain Carrot and His Amazing Zoo Crew! took place on an alternate Earth (Earth-C), which Superman crossed over into once. They have their own alternate too, Earth C-Minus, where the events that Rodney Rabbit writes in comic books take place for real.
- Enchanted, which examines how common Disney Princess tropes would work in the real world. Oddly enough, it wasn't supposed to be a Disney film at first, but became one.
- Toon Struck, an old quest video game, has this as its basic premise, with the protagonist, a cartoon animator, ending up in his toon world.
- Howard the Duck comes from a Type II.
- The film version of The Phantom Tollbooth.
- The Second Dimension in The Cartoon Man trilogy.
- Garfield Gets Real, where both the "real world" and Garfield's world are CG animated.
- The webcomic Hexenringe involves at least two dimensions - one like ours and one which is populated by comics characters and other fictional creations.
- Played for laughs in Community, when Abed manages to convince Troy that he's found a doorway to one of these outside Greendale Community College by painting an animated version of himself on a wall:
Troy: That's impossible!
Abed: Nothing's impossible in here! Animals can talk, your heart is shaped like a heart, and the smell of pie can make you float! You have to believe, Troy!
[Troy is just about to run headlong into the wall when:]
Abed: [leaping out from behind a bin] Wait! You don't have to believe.
Troy: [clearly heartbroken] I didn't!... I didn't... [he storms off]
Abed: I may have done some damage there.
- Ani-Earth in the Freedom City setting for Mutants & Masterminds is the Freedom equivalent of DC's Earth C-Minus, where the greatest heroes are the Furrydom League, and almost all damage is non-lethal (as explained in a sidebar titled "Boing!")
- Ghostbusters (IDW) establishes that there are two Ghostbusters universes: One in which Ghostbusters, Ghostbusters II, the 2009 video game, and the IDW series take place, and one in which the animated series The Real Ghostbusters and Extreme Ghostbusters take place, and the films are fictional. While there are some callbacks and references between the two (mostly in the form of background gags, although Janine's appearance in the comics is a hybrid between her cartoon and film appearances, and an alternate version of Kylie from Extreme Ghostbusters was part of the New Ghostbusters team), they remained mostly separate... until 2015, when IDW did a limited-miniseries crossover between both 'verses.