Petrosapien

Petrosapiens are a race of crystalline humanoids from the planet Petropia. They come in many subspecies, including Surface Petrosapiens and Subsapiens.

Physiology and Biology
While jewel-like in appearance, Petrosapiens are no pretty boys. Their diamond-hard bodies make these fearsome warriors incredibly tough.

Shards of the razor-sharp crystals jut out at numerous odd angles from their heads and bodies, discouraging physical contact, and also act as powerful weapons that can turn a car into confetti in a matter of seconds.

Combined with their increased strength, Petrosapien's shredding appendages can be especially devastating.

Being living prisms, Petrosapiens can refract light and beam-based weaponry, channeling them through their bodies and projecting them back at their source.

Weakness
Petrosapiens are particularly vulnerable to sonic vibrations. While a stereo blast might cause them to splinter, certain ultra-high-pitched sound waves can cause them to shatter, and no glue in this galaxy or the next can put a Petrosapien back together again.

Omnitrix Transformation
The Omnitrix's Petrosapien representative is named Diamondhead, who first appeared in the original series episode "And Then They Were 10". Diamondhead has appeared in every series.

The reboot version of Kevin 11 has a mutant hybrid equivalent of Diamondhead named Crystalfist, who first appeared in the episode "Franken-Fight".

Diamondhead has also been used by the Prime Timeline Gwen and Kevin, the "What-If" Gwen 10, Ben 10,000, Race Against Time Ben, Albedo, Vilgax's Bioid army, Ultimate Ben, the canon Gwen 10, and Mad Ben.