He first appeared in the very first animated series created by Disney, the Alice Comedies, making him the predecessor of Oswald the Lucky Rabbit and Mickey Mouse.

A bold and inventive hero, he gradually became the primary focus of the Alice Comedies, to the point Disney abandoned live action for pure animation on subsequent projects.

[4] In one of his first appearances, Alice's Fishy Story, Julius' tail demonstrates its great versatility, a recurring characteristic in the series.

This cat/mouse pairing was one of many famous animated duos from Krazy Kat (and Ignatz) through Tom and Jerry and Itchy and Scratchy.

She had been the distributor for Felix the Cat, but was constantly fighting with Sullivan, eventually leading to a split, so she turned to Disney to fill the void.

The Mickey Mouse cartoon Runaway Brain also features a character who, though visually modeled after Pete, is named Julius.