Cephalos are mini baby Cephadrome. They are fairly large though, but don't get confused, okay? Cephalos are aggressive and will attack on sight. Many of their attacks mirror Cephadrome's but are smaller. They can pop out of the sand and wriggle forward, causing you to fall on your butt. They can do tail whips. They can lunge forward a little to try and take a bite out of you. And they can also spit water balls at you that inflict Waterblight.
Cephalos, like Cephadrome, will chill out in the sand a lot . Use a Sonic Bomb to prey on their sensitive hearing and pop them, writhing, out of the sand.