From publisher blurb:
Have you ever wanted a giant, out of control, nuclear monster to toss at your heroes? Well, now you can!
This release of The Manual of Mutants & Monsters provides game stats on the Nuclear Toxyderm, an elemental spirit that is drawn to areas of nuclear activity and waste. Upon arriving from their dimension, these energies possess the nuclear materials and transform into a raging monster of nuclear toxins.
Includes game stats for the full-size and lesser variations, along with detailed rules on the risks of radiation exposure, and 3 new extras.