Energon is the main energy scorce of all Cybertroinians in its unrefined state it continuously emits a type of radiation wich can short circuit any form of circuitry including Cybertronian. Its crystal form if used correctly can be used as a weapon to cut metal with ease, in order for a Cybertronian to handle energon safely is to process the crystal state into a liquid form, in this state it can be easily converted in any form including the famed Energon Cubes which has been known to be just as volatile as earths nitroglycerin if its not handled carefully.
Types of Energon :
The most common form of Energon seen is the Purple semi-Liquid form this is the form in which it is safe for a Cybertronian to ingest or use to power their Weapons. It can also be used as a Plasma and a semi-solid, but is not always stable in cystaline form where it can react to sound, light or external energy and become dangerously and explosively unstable, In this state it sometime exhibits unusual properties like the abiltity to super-charge a Transformer or even defy gravity and causing itself and anything it's attached to fly.
The raw crystals are usually Blue but can sometimes be purple, yellow, green or pink. In the Majority of Transformers Continuities they Crystals are Blue or Purple, in The Transformers : Cybertron Universe Energon in its raw crystal state is yellow coloured and is poisionous to the touch to both Autobots and most Decepticons only a specific sub-species of the Autobots and the Decepticons call Omnicons (Sometimes called Omni-Bots) and Terrorcons (Not to be confused with other Transformers of the same name) these smaller Transformers have the natural ability to refine and manipulate raw Energon and stabilise it into a form usable by the other Transformers in the case of Terrorcons they turn the Energon into a Decepticon usable green coloured form, and in the Autobot form is red in colour. and additional super energon exists which is a very deep blue/purple colour or sometimes light blue and this is usable by selected members of either side but at great risk as it can also instantly kill the one who embibes it for the first time.
Yellow or Purple is sometimes used as an accent colour to show a powered State in a Decepticon and Red or Pink for an Autobot this can be seen in a variety of places such as the colour of accent plastics in some toys or the War For Cybertron Videogame and the Transformers : Prime Television show.
It is also quite common for Autobot Energy weapons to fire red blasts or if they are swords to glow red, and for Decepticon ones to glow or fire purple. and it is also common for Decepticons to have red glowing eyes and Autobots blue eyes the reason for this contridiction of colours is unknown ; as is how it might relate to the Energon itself or how it is processed.
There is a green from of Energon (akin to Toxic Waste) call Tox-En which is toxic to most Transformers (It may not effect the undead ones though) it causes weakness and debilitating pain and eventual system damage and death in an effect no unlike radiation poisoning on an organic being.
It is not known if the toxic effects would be blocked at all by Transformers with unusual abilities like some Maximals & Predacons (especially Transmetals) and Pretenders or Powermasters who have either protection from effects that would be toxic to an unprotected Transformer or the ability to filter unusual external effects of unsual energies or similar.
There is also a type of Synthetic Energon or Synth-En this had the advantage or being much more powerful than regular energon but has some sideeffect in the current form it has in its development - Syth-En is coloured green rather than the normal blue. it is believed a safe form of Synthetic Energon may have existed in the past but has been subsequently lost to time - The Transformers : Prime Universe's Ratchet is working on perfecting it though.
The most dangerous type of Energon is Dark Energon, otherwise known as the Blood of Unicron, which glows purple and brings Cybertronians back from the dead as mindless zombies.
Alternatives to Energon : (Supplemental Fuel sources)
Nucleon, Solar Power, Anti-Matter, Fusion Batteries, Electricity, Organic consumables.
Some Transformers either can survive with little or no Energon or are able to limit their consumption via powering either themselves or their weapons by other means. for example having an entirely mechanical gun, or having a weapon recharge by solar power or heat.
The Decepticon Scientist Shockwave supplements his energy with a Fusion power plant in his chest. his Transformers : Energon equiellent character Shockblast can similarly supplement himself with deployable solar panels.
Shockwave has proven able to function long past the point all the other Transformers have gone into stasis lock and reached a point of immobility and near death, with only Bumblebee's supreme fuel efficiency able to compete with that advantage.
Megatron seems to keep his Energon in the main for his body and instead powers the majority of his weapons with a small anti-matter fusion reactor. However this can put a lot of stress on him physically so he tends to use it at full power only vary rarely his energo-Mace weapon seems to be conventionally powered though.
Some Transformers have develop the ability to eat organic materials and convert them into energon, The Insecticons for example never need to fuel up they can survive simply by eating things and Shrapnel has the additional ability to attract store and manipulate electricity either from Human sources or from natural lightening storms which he can then redirect as a weapon. It seems that some Pretenders shell forms and Powermasters also are able to be fueled in similar ways ; A Pretender shell's health can either be maintained by Energy from the robot or by eating and any fuel gained is transferable either way. likewise Powermaster Transformer's companions can consume food or drink or filter other fuels like oil or electricity though their exo-armour to then refuel their robotic companion.
A powerful alternative fuel source exists that Transformers can also utilise called Nucleon this is a fuel source that is both a boon and a bane to Transformers as it has both the advantage or enhancing the strength and speed of an individual but with a number of potentially toxic side effects including freezing and an inibility to Transform, the effects do seem to be reversible if the Nucleon is flushed from the individual's body though - it is also speculated though that Nucleon unlike Energon isn't actually instantly toxic to organic being like Energon is but instead functions in a similar way as it does in Transformers but with still potentially fatal consequences. Nucleon continues to be utilised in times of dire need and is sometimes used to power vehicles or weapons where it's side-effects are less of an issue. Nucleon is believed to have self-regenerating properties - thought he mechanism through which it does this is not fully understood.
Energon is semi-toxic to Organic life in a way opposite to that which it is in Transformers a Human could safely handle a raw energon crystal where as prolonged exposure to a Transformer could be fatal where as refined Energon is poisionous to Humans even secondary effects powered by energon can have a deliterious effect on Humans causing symptoms of delerium, unconsciousness and potential death. However the effects do not seem to cause always lasting harm to any Humanoid binary bonded with a Transformer.