Winslow T. Oddfella appeared as a nuisance to Cat in CatDog. He is a blue mouse with a big nose and wears overalls. He tends to make CatDog's (usually Cat's) life even harder. Winslow has a signature laugh. Winslow also makes the situation even worse.
Winslow is clever, devious and mischievous. He considers himself as a "harassler", because he enjoys tormenting CatDog (well mostly Cat). In one episode, he blackmails Cat to be his personal servant after he caught him reading Dog's diary. Despite his sadism, he seems to like CatDog as a family. In one episode, CatDog is Winslow's one and only to bother, CatDog brings a female mouse named Sadie Linkletter to be Winslow's soulmate. But Winslow quarrels with Sadie at the beginning, and later started to have a crush on her.
Winslow is a blue mouse with a human-like nose and has black beady eyes. He wears green plaid overalls and purple shoes.