Tyrangrigus were stationed in the tombs of the most revered of ancient kings to watch over their possessions. Graverobbers that foolishly thought to steal would be buried beneath Tyrangrigus's endlessly-spawning limbs of sand.
They pretend to be elaborate coffins to teach lessons to grave robbers. A Tyrangrigus is so overwhelmingly powerful, it can bring down a whole mountain to make its nest.