Mr. Jolly is one of the four main characters in Teacher's Pet.
"A big blobby romantic tabby cat that smells like tuna fish and the outside world, he adores his soap operas, and is meticulous in personal hygeine. He will never in his nine lives understand why Spot would wanna go to school, be rivals with his master, and go "out there" into the terrifying land of sadistic animal control cops, coyotes, and traffic jams."
Mr. Jolly was raised by his mother and his father, Mr. Poppy Puddingpuss, abandoned him when he was still with his litter; his father later explained he left the family as he had no interest in the posh lifestyle his children, Mr. Jolly's mother and her relatives enjoyed. Eventually, he was sent to an animal shelter as a kitten and adopted by the Helpermans.
Mr. Jolly stays at home with Pretty Boy, Leonard's bird and they have adventures of their own while Scott and Leonard are at school. Too scared to leave the comfort of his home, he left the house only twice during the series, those episodes being: "Saving Mr. Jolly" and "Pet Project".
Mr. Jolly and Pretty Boy go on a road trip to find Spot and warn him about Dr. Ivan Krank after finding out that his experiments turn animals into mutants (although, that was because Krank needed mammals to make a human). After getting lost in Cuba and arriving by a viaduct, they make it to Leonard and they find out what has happened to Spot.
When Leonard is about to turn into a dog, Spot (as a man) shows up and they warn him about Leonard going to the lab. The three then proceed to save Leonard. At the lab, Jolly is turned into a butt-ugly man for a few seconds. When Krank is turned into a mouse, Jolly chases him out the lab.
At the awards ceremony, has a plan on how to get home. He dresses up as Scott and Jolly and Pretty Boy are holding onto the RV's back ladder.
Jolly is a romantic, gluttonous, neurotic, lazy, and cowardly tabby cat. He enjoys watching TV, eating tuna fish, and using the computer. Jolly is a pessimist, always fearing the worst will happen, but he also happens to have the best intentions and just wants his friends to be safe. He once wrote a letter to Regina Bobalina Fancypaws, a cat fashion model. He is in love with Tallulah despite her evil nature.
Jolly is a fat tabby cat with orange fur, a blue nose, and black stripes. He has blue sclera, just like Leonard.
- Mr. Jolly has an intolerance for soy milk ("What's Sweat Gotta Do With It?").
- His full name is "Mistopher Jolly J. Puddingpuss".