Paddywhack is the main villain in the episode "The Haunting of Mr. Banana Brain" of DarkWing Duck. He is an ancient evi spirit from another dimension and an obvious homage to Pennywise of Stephen King's IT. He may be the darkest entity in the duck universe since he feeds off negative emotions, pranks and general mischief. His appearance make the show grimmer despite the writers' attempts to keep it humorous.

Paddywhack was trapped inside a jack-in-the-box, but woke up after Gosalyn played a prank on her father while they were visiting a toy museum. When Quackerjack burst into the scene and starts playing pranks on everyone, Paddywhack gets stronges and is freed from the box. As the title implies he possessed Quackerjack's doll providing a macabre laugh when the mentally unstable toymaker only noticed a change in the liveless doll's voice. Since Quacky was already insane, yet easy to lead and childish he suited perfectly as the demon's puppet. That is until he decided to trap him and Drake to his twisted dimension to have an endless supply of suffering forever. The two, however team up and start goofing around which severely weakens the demon, forcing him to expel the two from the box. DW disposes of the box, throwing it at the river, and the box ends being swallowed by a fish. The end of the episode implies that Paddywhack somehow escaped the box and possessed the fish.

Paddywhack was voiced by the late Phil Hartman.