I Am Weasel is a great character: he's smart, strong (in some episodes), good-looking (or so he says) and a winner. He has managed to become a world famous scientist, doctor, dentist, hair-stylist and many other jobs (it depends on the story of the episode). Also, ha can (apparently) travel through time, as he has also appeared in certain episodes as a medieval knight, a cave weasel, an ancient Roman gladiator or as a viking.
His major love interest is Lulabelle, a blonde nurse, who follows him just about everywhere.
The other character (without whom the show wouldn't be the same), is I R Baboon, an idiotic monkey that can't count to three and can't talk correctly (hence the name: "I R"; it should be "I Am"); above all these "qualities", he's also a certified loser, presented beautifully in oposition with "the winner", I Am Weasel. Someimes friends, but mostly enemies (Baboon being jealous of Weasel's success), they form a couple like none other.
The cast wouldn't be complete without the Red Guy (from the "Cow & Chicken" series) who's IQ is somewhere in between Weasel's and Baboon's.