He guards his grandfather's castle where Samantha and Clover are searching for his grandfather and to rescue Alexandra. Both girls disguised as magazine reporters and Gregor lets them enter to show the artifacts. Therefore, he becomes suspicious to the girls as he lets them out of the castle shrine.
Later that evening, when Sam and Clover managed to rescue Alex, Gregor sends a wild dog to chase the girls and he was easily knocked from the chandelier by Sam while they attempt to escape. But the girls were captured by his grandfather, The Great Kandinsky by encased them with a mirror box from one of his magic tricks and he was shocked to see that his grandfather was alive.
When the girls were chained in the dungeon with a moving axe, His grandfather reunites with his grandson and tells him about his motives. Then the girls tells him the truth that his grandfather was behind the stealing artworks and artifacts.
Gregor begins to rebel his grandfather after refused to join him due to his crazy motives. He was hypnotized by his grandfather to join him by force.
During the jet fight, he was knocked down by the girls from a tomb stone artifact and they fight his grandfather. Gregor manage to caught the girls by using his grandfather's cloak. Sam manages to open the hangar to let his grandfather fall along with the stolen artifacts. He was saved by Clover from falling while he was hypnotized. When his grandfather was arrested by WOOHP, he returns to normal by Clover who snaps her fingers and became interested to her much for Clover to get blushed from him.
He is voiced by Michael Reisz.
Gregor appears to have blonde hair, tanned skin and green eyes. His appearance is wearing a red formal suit under a light pink button shirt with a turquoise and dark blue striped neck tie and reddish brown shoes.
- Gregor appears to be interested in Clover near end of the episode.
- His voice actor Michael Reisz also voices the young Kevin Ethan Levin in the cartoon series, "Ben 10" on his debut episode, "Kevin 11".