Halloween Wizard

Halloween Wizard is the name of a very elderly, red-robed, dark magical wizard. He lives inside of a large, supposebly haunted mansion, which was egged by Rigby due to him turning out the light when being asked by Rigby to give him candy in Terror Tales of the Park. He had later started lurking around Pops's House and then used his dark magic to turn Rigby into a nice-looking house. He had then murdered all of the park workers. He had killed High-Five Ghost by turning him into a liquid, then he burned Skips in a fire, injured Benson badly, badly injured Pops, trapped Mordecai into a closet and destroyed it, and then egged Rigby with a giant egg and drowned him. In the end of the episode, it had turned out that he had disguised himself as Rigby the whole time the stories were being told, and then he attacked the park workers, but not before signing off the show by saying "Happy Halloween!".

Trivia

 * He appears similar to The Wizard, only more elderly and wears a red robe instead of a blue one.