Living metal

The base material from which Transformers are constructed is known by many names, including living metal, protomatter, cyber-matter, sentio metallico, elemental metal, and Transformium. Often depicted as the living stuff of Cybertron itself, it is no ordinary metal, but rather, a living substance all its own, possessing a self-replicating cellular structure and a genetic code that defines and shapes a Transformer's natural alternate mode. This adaptable matter is also capable of being programmed to reconfigure into new shapes and designs, which is what allows a Transformer to change their alternate mode when they desire.

It is entirely possible for a new Transformer body to be built without using this elemental substance, using only regular metals; the resultant being is no less of a "real" Cybertronian, but may face some social stigma in an unenlightened society.

Notes

• The term "sentio metallico" was created by writer James Roberts for his unofficial Transformers novel Eugenesis, to refer to the living metallic stuff of Cybertron from which Transformers were birthed as seen in the Generation 2 comic. He would later introduce the term into canon through the IDW comic books, in which it was established to be the substance which makes up protoforms.