Pierobot

Pierobot (ピエロボット) is a clown robot enemy that walks on a large gear. Pierobot and Blocky were originally members of a robot circus, and they acted together in comedies. They appear in Metal Man's stage from Mega Man 2 and Mega Man II, and also appear as viruses in MegaMan Network Transmission.

Other media
Pierobots appeared in one episode of Captain N: The Game Master.

Trivia
The name Pierobot is a combination of the words pierrot and robot.