Skeletony is a character that only appeared in "Hide and Seek". He was formerly one of Uncle Grandpa's friends and RV mates. They used to play hide and seek together all the time, but one day Uncle Grandpa could not find him at all. After decades, Uncle Grandpa finds him, which awakens a wrath and thirst for revenge in Tony. He is voiced by Henry Rollins.
Skeletony is a living skeleton with the ability to create a blue flame around his skull. He has red pupils in the middle of his black eyes with a crack on his skull, and a gap between his teeth. He also has the ability to detach and reattach his limbs.
Skeletony, when not hellbent for revenge, has a great sense of devotion and dedication to the things he is passionate about. His dedication to his favorite game, hide and seek, is what caused him to remain in his hiding place for decades despite the fact Uncle Grandpa gave up on their game. His dedication is so great that Uncle Grandpa referred to him as a "bone head" when it came to the game.