The series chronicles the adventures of I.M. Weasel, an internationally famous, rather eloquent, highly intelligent and much talented weasel who is adored by everyone, and I.R. Baboon, an ugly and idiotic baboon who is envious about Weasel's success and constantly tries to be better than him. The show premise begins from a humorous take on the classic nursery rhyme "Pop Goes the Weasel"; in fact, the series theme song, composed by Bill Fulton, written by Richard Pursel, and sung by April March, is based on the well-known musical version of the rhyme.

The Wind in the Willows is a classic of children's literature. Alternately slow moving and fast paced, it focuses on four anthropomorphized animal characters in a pastoral version of England. Toad now hears from Rat that Toad Hall has been taken over by weasels, stoats and ferrets from the Wild Wood, who have driven out Mole and Badger. Although upset at the loss of his house, Toad realizes what good friends he has and how badly he has behaved. Badger then arrives and announces that he knows of a secret tunnel into Toad Hall through which the enemies may be attacked. Armed to the teeth, Rat, Mole and Toad enter via the tunnel and pounce upon the unsuspecting weasels who are holding a party in honor of their leader.