Nickelodeon! Cartoon Adventures is an anime series that focuses on many Nick shows (ex: The Mighty B!, El Tigre, Back at the Barnyard, T.U.F.F. Puppy, Fairly Odd Parents, Fanboy and Chum, etc.). All of the shows' characters interact with each other in a special environment that combines the settings of the shows.
- Bessie Higgenbottom-A pretty young girl who is part of the Honeybee scout troup. Originally she was 9 and 3/4, but in this series she's 13 (and later on 14). She's very smart and has many talents.
- Manny Rivera-A 13 (and later 14) year old boy with super powers. He can't decide between good and evil, but more often than not, usually acts as a hero. His Super-powered persona is known as El Tigre.
- Otis-A talking cow who desguises as a human when goes into town. Some of his non-animal friends know he's a talking cow, but in his own part of town, nobody knows about this (but Mrs. Beady is onto him!).
- Timmy Turner-A kid who has fairy godparents and a fairy godbrother. Jorgen Von Strangle, one of the most powerful fairies in Fairy World, allows Timmy to revel his fairies (Cosmo, Wanda, and Poof) to certain people, but in Dimmsdale he must keep it a secret. He was 10, but nobody knows his current age (he's in middle [and later on high school], however).
- Fanboy and Chum Chum-Two middle school (and later on high school) students who are total nerds. They love comic books, video games, action figures, and Frosty Freezy Freezes. Fanboy is about 13–15 years old, and Chum Chum is a year behind him (thus making him range between 12-14).
- SpongeBob SquarePants-A frycook who is actually quite young (he's in the 9th grade at the beginning of the series). He was originally a square shape (hence his last name), but due to the show's style, he is now antropomorphic.
- Jimmy Neutron-A genius who is only in the 8th (and later 9th) grade. He has a very strange haircut that completelly defies gravity.
- Mikey Simon-An American kid who lives in Japan and has an acting career. He and other characters can go back and forth from NickTown (the town that binds them together) to Japan and vice versa, but a running gag in the show is that they never explain how they do it. A gag in the original series Kappa Mikey was that Mikey was animated American-style while every other non-American character was animated anime-style, but now Mikey is anime style and often breaks the forth wall mentioning that he's glad that he's in an anime style.