The Comanche Cataphract

Sketch of a late XVIIth century comanche cavalryman, sporting armor of leather with glued sand. Made of folded deerskin for the horse and buffalo hide for the man, the armor set was said to have been impervious to the stone and steel arrows of his enemies.

It was with this kit that the Comanche and their Shoshone bretheren (from whom they had split only a few decades earlier) expanded into the central plains, waging war against local natives, some of whom had yet to encounter horses or horse riders, as well spanish colonizers and their indigenous allies from the south.
The Ponca would record in their oral traditions that: