Kloak from Donkey Kong Country 2. One of the cooler undead Kremlings, seemingly a dead Krook who possessed his jacket.
This blatantly should not be in the ported model category given this is free use and not ripped from a game, but whatever.
Original model created by Peardian.
Original animations by Guide2Jesus/G2J.
Conversion to Warcraft 3 and animation tweaks by Warlord.