Bestia Oscura
During the "Secret Wars" storyline, a version of Dark Beast resides in the Battleworld domain known as the Domain of Apocalypse. He is shown to have Doctor Nemesis as his assistant in his experiments unaware that Doctor Nemesis has been tampering with a sample of the Legacy Virus. The X-Men defeated Dark Beast in order to get their hands on the Legacy Virus just as Apocalypse arrives and plans to use the Legacy Virus into seeing who would survive it.