Tox-En

Tox-En is a form of Energon from the Aligned continuity family.

Tox-En is a toxic version of Energon, a sample of which was formerly stored in the Vaults of Iacon. It has the opposite effect as regular Energon on Transformers, causing them to feel nauseous and weakened by the slightest physical contact. Prolonged exposure to Tox-En can outright paralyze a Transformer, eventually extinguishing their spark.

Needless to say, it's pretty nasty stuff which sane individuals will dispose of on sight. A complete lunatic, however, can use it as a devastating weapon against their enemies.

Fiction

Prime cartoon

Plot details for Toxicity follow. Spoilers have expired, you may remove this tag

Megatron found a way to refine raw Tox-En during the war, converting it into a bioweapon that devastated the Autobots. A sample, formerly held in the Vaults of Iacon, ended up on Earth where it was found by Bulkhead near a volcano at the equator. Deeming it too dangerous to leave intact, he sought to destroy it in the fiery depths of the volcano. To stall Megatron's own search party - Hardshell and a group of Insecticons - Bulkhead left a small chunk of Tox-En in the canister, along with a grenade that destroyed the chunk and left one Insecticon with a neck full of toxic shrapnel.

After leaving a false trail of Energon to keep the Decepticons busy, Bulkhead took the remainder of the Tox-En with him on his trek to the top of the volcano. Unfortunately, his earlier ruse forced him to actively carry the toxic substance, rapidly weakening his body and mind as he struggled up the slope. Although the encouragement of Agent Fowler gave Bulkhead the strength to reach the crater, his fatigue allowed Hardshell and his remaining minions to catch up to him before he could destroy the Tox-En.

During the ensuing confrontation, Bulkhead used the Tox-En as a makeshift weapon against his foes, completely incapacitating one Insecticon and sapping Hardshell's strength. After a brief battle between the exhausted Cybertronians, Bulkhead further weakened Hardshell by forcing his face into the Tox-En. As Hardshell staggered back, Bulkhead tossed the Tox-En to him, causing the disoriented Insecticon to fall into the volcano. Although Hardshell survived, the Tox-En was dissolved in the molten rock. Toxicity

Notes

• The name "Tox-En" name is likely a pun on the word "toxin" or derives from "toxic Energon".
• Between its appearance as a glowing green crystal and its potentially-lethal effect on Transformers, it bears a strong resemblance to Kryptonite.