Ghastly Fiend is a fiend created by A Boy to scare random people in Onionville. He looks like a jack-o-lantern with wolf ears, a single eye with muscles surrounding it's optic nerve, allowing the eye to have more flexibility, spider legs, and bat wings. In addition, the jack-o-lantern head can breath fire and it's mouthis a portal to the Netherworld.
Trivia[]
Ghastly Fiend was the main fiend in the first Halloween special of A Boy and A Girl. In the second Halloween special, a child dressed as him makes a background appearance.