Big the Cat is a fictional character that appears in the Sonic the Hedgehog series. He is a large, anthropomorphic purple cat who lives deep within Mystic Ruins. Though imposing of stature, Big is a gentle and easy-going, though somewhat dim-witted person with a heart of gold. Froggy is the pet frog and best friend of Big the Cat, though he has a habit of running off on his own, leaving Big to set off each time to find him. Sonic cursor with fanart Big the Cat and Froggy.