Ghost (Wario Land 4)

Yūrei (幽霊 or ゆうれい ) is an enemy in the Game Boy Advance game Wario Land 4. It only appears in the level Crescent Moon Village. Yūrei cannot be attacked or defeated by Wario, explaining its ghost-like appearance. In fact, it can't hurt Wario either. It only steals Keyzer, the bird-link ghost that Wario needs to obtain in every level in order to advance through the game and lose change on the ground. Yūrei will steal any type of Coin, but will not steal Blue or Red Crystals or Diamonds that float in the air. Yūrei only appears in the larger areas of Crescent Moon Village.

Its name refers to figures in Japanese folklore that are analogous to Western legends of ghosts.