Like the other armadillons, it's a Sentinel for the party. There exists on Final Fantasy XIII-2 disc data regarding an unused armadillon Sentinel called Glyptodon with complete Crystarium. It caps at level 99, comes initially learned with Auto-Haste as well as Resist Magic: +36%, Resist Physical: +26%, and Resilience: +15%. It's "dummied" status may be explained with Glyptodon starting with Haste which is hard to come by in Final Fantasy XIII-2 and would make the game too easy.
[view·edit·purge]Glyptodon (Greek for "grooved or carved tooth") was a large, armored mammal of the family Glyptodontidae, a relative of armadillos that lived during the Pleistocene epoch. It was roughly the same size and weight as a Volkswagen Beetle, though flatter in shape. With its rounded, bony shell and squat limbs, it superficially resembled turtles, and the much earlier dinosaurian ankylosaur, as an example of the convergent evolution of unrelated lineages into similar forms. Glyptodon is believed to have been a herbivore, grazing on grasses and other plants found near rivers and small bodies of water.