Zipacna are a powerful breed of Giant from South America, and long-time foes of the Atzlanti. Even by the standards of elder giants they are large and strong creatures, standing 30 feet tall. Unlike most giants they are relatively handsome in appearance, though their otherwise human demeaour is interrupted by their yellow, reptilian eyes. They are substantially more intelligent than most giants, possessing some degree of Epic Intelligence.
What sets the Zipacna apart from most giants, however, is their shape-shifting capabilties. Each Zipacna is able to transform into a gigantic caiman (a type of South American alligator), and in this form it enjoys the increased protection of a thick, scaly hide as well as fearsome jaws and the ability to swim rapidly in water. When Zipacna breed, a female lays a clutch of eggs which hatch into baby caimans; these proceed to attack and devour each other until only a single one remains. This infant then grows to adulthood within a matter of seconds.
The Zipacna, of course, take their name from their ancestor, a Primordial Giant called Lord Zipacna and who, to this day oft hides amongst from the Gods amongst the living.