Hi Five Ghost's Father

High-Five's Father appears in the episode "See You There", where in the prank he pretends to be a doctor who announces that Muscle Man is dead.

He looks just like High-Five Ghost except he has a white beard and a couple wrinkles.

After the prank he tells Rigby that he isn't a doctor and that he was part of Muscle Man's prank.

He was the fifth family member at the park. The first being Don then John then Mr. Maellard and then Low-Five Ghost.