Nightmare Leech

Nightmare Leech is a Digital Lifeform. Nightmare Leeches are familiar spirits to NeoMyotismon, which are brought forth in an inexhaustible supply, and naturally prefer the life energy of Digimon.

Etymologies
Official romanization given by the Digimon Reference Book and used in Japanese media.
 * Evilvil (イビルビル)

Name used in Digimon Fusion and American English media.
 * Nightmare Leech