Bonehead Jed

Bonehead Jeds are enemies found in Donkey Kong Country Returns and Donkey Kong Country Returns 3D. They are found in the Cliff area of Donkey Kong Island. Bonehead Jeds are basically undead dinosaurs inside carts, but when Donkey Kong or Diddy Kong get close to them, they'll extend their heads in an attempt to attack the Kongs. The Kongs must stomp on their heads twice to defeat them; the first hit temporarily immobilizes them. Kong Rolls have no effect against them.

Although Bonehead Jeds are depicted as being able to fire tar projectiles from their mouths in the concept artwork, this is not the case in the final game. There is, however, a fire-spitting variety, known as Firehead Ned.

Reference
Knochenkopf-Karl