Fistilleum

Fistilleum is a substance that is gaseous at temperatures of minus three thousand dreams, and extremely volatile when it comes in contact with a Cybertronian’s spark energies. It also happens to have a rather unpleasant smell.

Fiction

Wings Universe

Tornado compared the smell of Fistilleum to the smell of a Gelnac Mule's backside. Tornado - Decepticon Saboteur