Mr. Kitty seems to suffer from abuse on Cartman's behavior, usually when she attempts to get some of Cartman's food, to which Cartman always replies by yelling, "No Mr. Kitty! that's MY (name of food)" several times, each time his voice becoming more aggressive. This is suggested in "Cartman Gets an Anal Probe", when Cartman calls Mr. Kitty a dildo, to which Liane comments "Well, I know a certain kitty-kitty who's sleeping with mommy tonight."
Mr. Kitty would later have a prominent role in "Cat Orgy", in which her gender has shifted back towards female and she is in heat. After attempting to have sex throughout the episode, Mr. Kitty assembles a massive group of male cats to come home with her. She then proceeds to get all the cats high on catnip (which they snort like cocaine) and all the male cats proceed to take turns having sex with Mr. Kitty. Cartman and his babysitter Shelly Marsh were, needless to say, horrified.
Mr. Kitty's next real appearance would be in "Major Boobage", in which Cartman, Kenny, Kyle and Stan attempt to test whether or not it's possible to get high off of male cat urine (Mr. Kitty is again male in this episode). The test proves to be successful, as Kenny gets high and ends up in a hardcore drug fantasy, that he becomes addicted to. When "cheesing", as it is called, becomes a major drug issue in South Park, the cats of the town are rounded up by the authorities. Showing uncharacteristic concern for his cat, Cartman proceeds to hide him/her in the attic, in which Cartman gives him/her a diary so as to record his/her life, in a manner similar to Anne Frank. Later, Cartman begins to hide more and more cats up in his attic with Mr. Kitty, until Kenny, completely addicted to Cheesing, breaks in and uses them to get completely wasted. After Gerald Broflovski, the key opponent to cheesing, is caught doing cat urine himself, the ban on cats is lifted and Mr. Kitty is free to live with Cartman like before.
Mr. Kitty returns in "Faith Hilling", where she was caught by Cartman posting pictures of herself on the internet with bread around her head. After Cartman and the boys finally realized that "Faith Hilling" was out of style, they used Mr. Kitty to perform various other memes. When they went to do the meme at the Colorado Republican Debate again, Mr. Kitty was seen being held by Eric when he was to perform the meme. Instead of using the meme that involved Mr. Kitty, Cartman instead "Faith Hill'd" the audience, which praised it for being well done.
Mr. Kitty is a gray cat with dark gray ears, and black whiskers. Prior to her appearance in "Major Boobage", Mr. Kitty had a black nose, with the exception of her original appearance in "Cartman Gets an Anal Probe" where she had a pink nose. Her updated appearance includes more detailed fur, a more detailed body style, and a tiny pink nose.
- "The Unaired Pilot"
- "Cartman Gets an Anal Probe"
- "Tom's Rhinoplasty"
- "Cartman's Mom is a Dirty Slut"
- "Summer Sucks" (Mentioned)
- "Chickenpox" - Cartman uses her to scratch himself.
- "Rainforest Shmainforest" (mentioned)
- "Cat Orgy"
- "The Death of Eric Cartman" (mentioned)
- "Major Boobage" - He/she hides in the attic to avoid being taken and the boys use him/her on Kenny to see if they can get high off cat urine which proves to be a success.
- "Faith Hilling" - Caught posting images of himself/herself online.
Mr. Kitty is seen in Cartman's backyard and inside his house.
- Regarding the contradictory pronouns for Mr. Kitty, it was revealed that she is a hermaphrodite on the FAQs section of South Park Studios.