From Fish Hooks Wiki
Snake is a Western Diamondback Rattlesnake that is friends with Mouse. They live together in a tank in Bud's Pets. Snake mostly appears in the credits of episodes. She appears in the episodes "Funny Fish", "Halloween Haul", "So-fish-ticated", "Cattlefish, Ho!", "Fish Prom" and the short "Merry Fishmas". Snake is voiced by Kari Wahlgren.