From the Super Mario Wiki
During his story, Jimmy T. is walking down Sapphire Street when a stray cat jumps into his hair. Amy and Mimi notice the cat, and ask Jimmy if they can take pictures. He obliges, and when the girls are done, Mimi sends him the best photo, which is one of the cat. At first, Jimmy is shocked, but then brushes it off after Amy and Mimi leave.
In the game's credits, Sapphire Street is seen in front of an image of Jimmy T. and the cat.