Mephistomon

Mephistomon is a Dark Animal Digimon whose name is derived from the fictional and whose design is derived from the mythological. It has the appearance of a giant ram, and is a dark being born from the lingering thought-data of an Apocalymon that attempted to destroy all life. Like Apocalymon, its governing principle is the extermination of all life. It specializes in the black magic of the Dark-species, and its personality is endlessly cruel. However, it is extremely intelligent, and is also a tactician.

Digimon Tamers: Battle of Adventurers
Attacks
 * : Recites a dark incantation in which it prays for a festival of death; those who hear the spell soon die.
 * Dark Cloud (Death Cloud): Generates a cloud of darkness which causes everything to decay.