Gregor tired of the tradition upheld by Vampires and led a faction that invaded and occupied Lupusville, a town privately held by Werewolves.  He clashed with a faction of traditionalists that preferred to live underground. Unable to destroy them, Gregor journeyed to New York City and hired the Ghostbusters to get rid of the rival Vampires under the pretense they were the only Vampire threat. When the Ghostbusters failed, he then kidnapped Egon Spengler and Winston Zeddemore and it was revealed he was a vampire, too. He was last seen fighting in a battle against Vampires and Werewolves. His fate was left uncertain.
- Every time Gregor's name is spoken aloud, lightning strikes.
- On page six of Ghostbusters Issue #14, Gregor's treasure chest makes a non-canon cameo on the bottom shelf.
- ↑ Gregor (2009).The Real Ghostbusters- "No One Comes to Lupusville" (1987) (DVD ts. 03:28-03:30). Time Life Entertainment. Gregor says: "My name is Gregor."
- ↑ Gregor's rival (2009).The Real Ghostbusters- "No One Comes to Lupusville" (1987) (DVD ts. 12:05-12:23). Time Life Entertainment. Gregor's rival says: "Once we were united under my leadership. We shunned the open towns. Then Gregor, his followers, his servants invaded Lupusville, capturing all who lived there. They grew tired of the old ways that have protected us. They risk exposing us to the world."