Moink

The Moink is an enemy in Spirit Tracks. It can only be found while riding the train, and it resembles a white pig with black spots on its body. Link can blow the whistle at it to scare it if it is on the tracks. If not, the train will crash against it and the Moink will turn red and charge at it. They disappear after obtaining the Ocean Rail Map. If Link shoots one, it will charge him and attack.

Trivia

 * "Moink" gets its name from "moo" and "oink", as it appears to be a pig with cow spots.