Kenneth "Kenny" Cassidy is the titular protagonist of the show. He is voiced by Jim Conroy.
Kenny is a comical tiger shark with a go-lucky attitude. Kenny was tired of life in the ocean and he went on the surface, where he is able to walk on his tailfins and breathe air like humans. He can't control himself when he hears or sees a seal. Kenny lives with an 11-year-old girl named Kat (who is the only human that can talk to Kenny) and her family. Kenny lives in a house by himself. He loves eating Chum and two foods that he love, Eel Pops and Seal Pops. Age: Approximately 14 years.
- Kenny was around long before his show, as a series of shorts that ran between programs in the late 90's.
- In Pet Tricks, he demonstrates his ability to eat up old junky things and spit them back out as awesome new things.