Gramps the Vamp is a villain from the Scooby Doo franchise. Uncle Leon claimed to Lisa Banton that the vampire in question was her late grandfather. It supposedly took control of her in order to haunt Great Skull Island. When the vampire was defeated, it was discovered to be Uncle Leon in disguise, in a plot to keep his niece from claiming the hotel.
He used a special whistle to control his vampire bats, which he bought at an exotic pet shop. Velma Dinkley realized this when Scooby-Doo and Scooby-Dum could hear it and she couldn't. He also used a watch to hypnotize Lisa into thinking she was a vampire and attacking Shaggy and Scooby. Gramps also fell prey to one of Shaggy and Scooby's "ball-and-cup" games, this time with coffins.