Bukubuku

Bukubuku (ブクブク ) are underwater enemies from Donkey Kong for the Game Boy. They are round predator-like fish and first appear in the Forest in Stage 2-5. Bukubuku swim around horizontally, but home in on Mario and try to bite him if he draws near and they face him. If Mario is touched by one of them, he loses a life. Bukubuku can only be defeated by hitting them with a throwable object, such as a key.