Marnie is a minor character featured in the episode "Bizarre Bazaar".
Marnie is a light green frog, with a lighter green underbelly and chest, with moss-green spots on his cheeks. He has tiny black pupils and two small front teeth. He wears a brown suit with a green bow.
He is shown to be an excellent thief. He stalks the visitors of the Bizarre Bazaar, taking possessions and stealing money and coins from them. He also wears a black hood and mask to conceal his identity. Marnie also takes advantages of the rules of the Bizarre Bazaar as he knows that anything in his stall is in his rights, no matter where he got it. He often places his stolen goods as prizes in his cockroach kart-game stall, such as the Calamity Box which he stole from Anne.