A recurring enemy from the [[mario_(series)|Mario series]].

Their basic appearance is of an animate, carnivorous [[ball and chain (weapon)|]]:  a black circle or sphere with a large, [[sharp teeth|toothy]] mouth, beady eyes, and a metal [[chain]] attached opposite the mouth. The other end of the chain is typically fixed to a sturdy, immobile object.

They behave like guard dogs, lunging at any enemy in range:  their Japanese name, "Wan-wan," is an onomatopoeia for the sound a dog makes, analogous to "Woof-woof" or "Bark-bark".

They occasionally make cameo appearances in other [[Nintendo]] games.  In particular, [i][[The Legend of Zelda: Link's Awakening]][/i] features a friendly, domesticated Chain Chomp named BowWow which will attack Link's enemies.
ワンワン