Penkoon

Penkoons are bulky soldiers that patrol areas in Wario Land: Super Mario Land 3. When Wario comes too close to them, they make the spiked ball in their stomachs pop out. Despite their horned helmets, Wario can harm them by jumping on them; however, due to the spikes on their stomach, they cannot be harmed by charging head on by the Body Slam.

Trivia

 * In the Japanese manual, their resemblance to both a tanuki and a penguin is noted, but their species remains a mystery. In the English version, they are instead described as "part penguin and part racoon." [sic]