IM WeaselThe main protagonist, a heroic weasel, who is everything I. R. Baboon wishes, and possibly imagines, he was. Weasel is often seen volunteering to help those less fortunate than himself, or contributing great deals to society by erecting monuments and structures with beneficial results.Voiced by Michael Dorn
IR BaboonThe other main character of the series. Most times he is seen taking a back seat to Weasel's escapades, and feeling resentful and jealous towards him. But there are those rare occasions when the two act as the best of friends.Voiced by Charlie Adler
The Red Guy/I.B. Red GuyThe same character from Cow and Chicken (only he goes by I.B. Red Guy or the many names that refer to his not wearing pants), who acts as an antagonist of the series, whenever I. R. Baboon isn't fulfilling the role.Voiced by Charlie Adler
LullabelleThe Weasel's blonde and attractive nurse assistant. As a minor character, she made most of her appearances in Season 2 and became out of focus. She is often speculated as Weasel's girlfriend.