BuckBot

BuckBots are robotic wind-up chickens that appear in Donkey Kong Country Returns and Donkey Kong Country Returns 3D. They only appear in the Factory area of Donkey Kong Island. BuckBots move around by marching back and forth like a wind-up toy, and they attempt to run into Donkey Kong and Diddy Kong. BuckBots can be destroyed from any attack, causing them to break apart in a puff of smoke.

BuckBots also have an explosive counterpart, BuckBombs, which self-destruct shortly after being attacked. Both enemies were most likely created by Colonel Pluck, considering BuckBots are released from eggs by the Stompybot 3000 during the boss level, Feather Fiend. Some of the released BuckBots drop hearts when defeated.

Reference
Gackerbot