Minicula

Miniculas are bat-like enemies that appear in the game Wario Land 4 that can't be defeated by Wario or in any other kind of way (similar to Kobatto from Wario Land 3). These vampire bats can turn Wario into Bat Wario when Wario touches them. The vampire bat effect wears off when Wario flies into the light or fall into water. These enemies only appear in three levels in the Sapphire Passage: Crescent Moon Village, Arabian Night and Hotel Horror, and also appear in the Golden Passage level. They aren't known to be aggressive to Wario, despite them being enemies.