Ghost Guy

Shy Guys are undead ghosts that appear in the game Luigi's Mansion. They are usually red or purple with Shy Guy masks, and are equipped with pitchforks resembling those carried by Beezos from Super Mario Bros. 2 and the non-Mario game Yume Kōjō: Doki Doki Panic. When Luigi uses the vacuum on them, the masks come off revealing two yellow eyes and a small black hole for a mouth that are actually set on the hoods that they wear. Removing their masks also allows them to be stunned with the flashlight and vacuumed. A group of dancing Shy Guys appear on the Roof near a fire, and in the Ball Room, where the Floating Whirlindas appear after Luigi catches them.

Reference
Shy Guy (Geist)