A spirit named Paddywhack is unleashed from a jack in the box when Gosalyn gets into mischief, and possesses Quackerjack's doll, Mr. Banana Brain. As he causes trouble alongside the toymaker, he grows, feeding from the negative emotions around himself.
"I am the yoyo that keeps coming back, or something."
This episode marks the first appearance of Paddywhack.
Quackerjack's hands are orange when he talks about the damage pizza does to one's complexion.
The adult pig patron's moustache is missing in his first shot.
"The Haunting of Mr. Banana Brain" is the closest the Darkwing Duck cartoon comes to giving Quackerjack an origin episode. He reiterates what drove him to criminality from his introduction in "Whiffle While You Work" and this is the one episode that shows him out of his costume.