Bonehead Chompies are enemies in the Land of the Undead during Skylanders: SuperChargers, and BattleBrawl Island and the Sensei Dark Realm during Skylanders: Imaginators.
They appear to be Bone Chompies with bone helmets, or skeletal Armored Chompies. They attack by biting the Skylander like another Chompies, but they are tougher due to their bone helmets.