While generally it is only naturally found on Cybertron, it can be seeded on other worlds. Little is known except that it is Plasma Based. It comes in two general variants, the Blue form which is the naturally occurring version and highest quality grade, and the pink version which the artificially created one from other fuels. Energon is considered the, or one of the, cleanest forms of fuel in the universe.
Energon comes in different forms, liquid, gas, crystal (the normal and seeded versions). In its raw, crystal state, its radiation is hazardous to Cybertronians and is rather explosive. Even in its refined liquid state, it still maintains is explosive properties.