Buffy the Vampire Slayer: Classic #23-#28
Issue #27: The Hollower
Angel has an encounter with someone from his past, and now has to face a threat he had hoped had been long destroyed: the Hollower. The Hollower is a natural predator of vampires. The hideous thing might be linked to Angel's salvation or his destruction.
Issues #23 - 28 Issue #28: Graduation Day