He's a Crocodile

Gavin is a crocodile. He loves to roll over and over and over like a crocodile does during its infamous "death roll." Anytime you place him on his back, he will almost immediately roll over onto his stomach (probably because he's also a tummy time addict) and then after a few minutes, he'll roll back over onto his back, and then onto his stomach again, and so forth. That's why Gavin is a crocodile.