Sir Frosty

Sir Frosties are living snowman enemies that only appear in the snow-covered portions of the Snow Realm while riding the Spirit Train. They pop up from the ground either alone or in pairs and attack by throwing their heads at the train. To defeat them, the body must be shot with the cannon. If the head is shot, it will simply grow another one shortly after. If one successfully throws its head, though, it must be shot to avoid damage. If they are shot just as they throw a head, both can potentially be destroyed at once. They are completely immobile, and as such can be simply evaded without defeating them.