Chipper had a minor role in his one appearance in the series. He asked Doidle, who was really Timmy Turner in the dog's body, if he was given a steak earlier and he replies yes, causing Chipper to laugh and walk away. Presumably, Chipper was also given a steak along with Vicky's other pets before he was taken to Dr. Snipowitz.
He is a beige tabby cat that is seen twitching a lot. When he speaks to Doidle/Timmy, he has a gruff adult male voice.