Kyoufu no Kyou-chan

A parody of "Obake no Q-taro" written by the comedian Hitoshi Matsumoto, the series is about a kid and his ugly critter (with a strange likeness with Butthead). You better not hurt the kid or Kyou-chan will grow arms on his head and feet on his mouth to rip off your guts!

(Source: TVTropes)