Krockhead

KrocHeads, also spelled Krockheads, are crocodile enemies that first appeared in Donkey Kong Country 2: Diddy's Kong Quest and later Donkey Kong Land 2. Only the head of a KrocHead is ever seen. Despite being an enemy, they do not harm the Kongs directly. Instead, their heads are helpful to them, the green variety acting as platforms and the red as springboards. They can be found in either water or lava. In some levels, KrocHeads bob up and down, making timing a necessity. Sometimes, they must be summoned to the surface using a Krockhead Barrel; however, this summoning is only temporary.

Although it's possible that these are a type of Kremling, their relationship to Kremlings is never confirmed.

Trivia

 * the KrocHead bears something of a resemblance to the giant sarcosuchus of ancient times, and due to the bulbus tip of the snout.