From the Super Mario Wiki
“What!? Are you ready to challenge me? Here's a secret-- I hate to lose!”
Harley Q is the third boss Toad faces in the VS COM mode in the Super Nintendo Entertainment System version of the game Wario's Woods. She is a creature that resembles a Harlequin, or a jester from the 17th century's Commedia dell'arte, who either wears a bodysuit or has purple skin. She also wears a dress-like contraption that spins around unceasingly.