Huitzil's race were created when Pyron first visited Earth millions of years ago. After wiping out the dinosaurs, they traveled underground. There they slept for millions of years. Around 520 AD however, they were discovered by the Mayans, who used them for themsleves, and for a multitude of purposes.
Eventually, they were placed into the Teotihuacan Ruins, and went into another long sleep. When Pyron later returned to Earth, they reawoke, to complete their orders once more. However, due to a unforseen malfunction, Huitzil carried out new orders: To protect a young boy named Cecil, who had stumbled upon it by accident one day. When the unit who had befreinded Cecil was destroyed protecting him from Jedah it activated the other units to protect the boy.
Huitzil's entire body is in fact, one giant weapon. In addition to the standard physical attacks and icy eye beams, Huitzil is able to edit his body through unknown means to create weapons to use. He's been shown turning his arms and legs into buzzsaws, drills and massive claws, as well as extend blades from his kneecaps. He's capable of turning his arms into massive gatling guns, or pull them into his shoulders and then proceed to fire rockets out of them. However, nothing is failproof, and should Huitzil try to activate the wrong weapon, a chunk of ice will simply fall out of his shoulder, and he'll try to rip his head off in a bout of confusion. He's also capable of achieving flight in two different ways. The first by retracting his arms into his shoulders once more, and using them as a sort of impromptu jetpack. The other involves him turning his legs into a black upsidedown pyramid with purple orbs floating about it. He then proveeds to levitate about the air.