Zazzles is one of Sheldon Cooper's 25 cats in "The Zazzy Substitution", adopted to help Sheldon get over his and Amy's "breakup". He is the only cat in the "clowder" not named after a Manhattan Project physicist. Sheldon claims Zazzles was simply too "zazzy" and he couldn't help not naming him Zazzles. His previous name was going to be Dr. Hermann von Helmholtz.
At the end of the episode, Sheldon and Amy set up a booth and pay each child $20 to take each cat including Zazzles.
His actions definitely show that Sheldon is a cat person though in "The Fuzzy Boots Corollary" Sheldon discouraged Leonard from getting a cat. Also he had admitted in an early episode that he was allergic to cat fur.