The Zantaboan is an ancient beast in the Zantaboan Saga.
The Zantaboan loosely resembles a tyrannosaurus rex. With horns on it's head and longer claws, also it can sprout wings which it can use to fly.
The Zantaboan Saga Edit
In the Zantboan saga the Zantboan is a monster that is being assimilated into the Zerg Swarm. A small group of exiled templars are sworn to destroy the monster, but in the Zantaboan has minerals growning on it's hide which absorbs energy which the Protoss now wields as weaponry. So they turn to the Terrans with their basic weapons which does not use energy that the minerals absorbs.