Scrap Elf

Scrap Elf (プアエルフ) is the corrupted Cyber-elf enemy in Mega Man Zero 4 that appears in the Hibernation Chamber, Fenri Lunaedge's stage, in capsules that shatter when the player gets too close. They enter in Pantheon Corpses to reanimate them. Scrap Elves can only be defeated by taking Lamps with the Zero Knuckle to push them to the light in the end of the area they appear when the weather is sunny. Because of this, Scrap Elves are invincible in Hard Mode, where there is no sunlight to kill them.

Trivia

 * The minigame Elf Chase involves using a lamp to drive a Scrap Elf to sunlight at the end of the area.