Moxie is the tritagonist of the television series' episode "All Creatures Great and Dinky." She is the only mouse to ever have any speaking roles, and she is a mother mouse. In fact, she is apparently the matriarch of her family. She doesn't like Charlie and Itchy at first for their slobby lifestyle, but when the latter two are shrunk (due to Charlie's excuse that they are too big for a mission in helping the mice escape pollution), she gets along with them. She is the one who reveals them where the source of toxic paint is coming from, but where it comes from is more familiar to Charlie and Itchy than to her, as they know the polluters who turn out to be Carface and Killer.
It is shown that only one of Moxie's relatives is named: Maurice. However, whether he is her mate or not is unknown.
Moxie doesn't like it when her children come into contact with Styrofoam because of likeliness that they can swallow it, and it bothers her because that material stays in their tummies forever if they do swallow it. So, she has them play with a wad of paper instead.
In the end, Moxie arranges a round of cheese fondue for Charlie and Itchy as thanks for saving her family from pollution, but as soon as they leave, they return to normal size. Charlie then holds Moxie in one of his paws and feeds her cheese with the other.