Junk Golem (ジャンクゴーレム,Janku Gōremu?) is, as its name implies, a robot made of junk. Dr. Wily created it in a hurry when he discovered Mega Man was inside his fortress. Junk Golems appears only in the fourth Wily Castle stage in Mega Man 3, and also is the only enemy there (other than the rematch against the Robot Masters in the teleporters). They throw Junk Blocks at Mega Man.
If the Junk Golem is destroyed as a junk block falls, the junk block will still be hurled even though there is nothing there to throw it.