SkullCrusher

John "SkullCrusher" Terwilliger is a villainous resident of the Underworld. He is the main antagonist of the Tia and Friends series. His death-long-goal is to obliterate Horror and Tia so he may become King of the Underworld. He makes his first appearance in "Teacher Trouble".

In the end of Teacher Trouble, SkullCrusher is placed under arrest and is currently in prison.