Hester's history is unknown, until the day he escaped from prison. Hiding out in a leaky industrial plant, he was exposed to a toxic cocktail of chemicals which mutated him into the superhuman creature known as Slag. He helped found the mercenary team known as Tri-Ad, and fought the WildC.A.T.s.
- Thermal-Blast: Slag could project intensely hot lava blasts.
- Superhuman Strength
Slag has appeared in the following non-WildStorm Image publications: The Deadly Duo Vol. 2 #3.
- 13 Appearances of Heinrich Hester (Wildstorm Universe)
- 1 Images featuring Heinrich Hester (Wildstorm Universe)
- Quotations by or about Heinrich Hester (Wildstorm Universe)
- Character Gallery: Heinrich Hester (Wildstorm Universe)