Grunge, whose name is Percival (Edmund) Chang, was born in Hong Kong, but his father, Philip Chang, kept his existence and abilities secret, and Percival was raised in Seattle, Washington. Grunge eventually ended up with other members of the I.O. Project Pegasus, only to discover he and the other "Gen-Actives" were essentially in a prison being monitored and experimented on. Grunge eventually escapes with Gen13 member Freefall.
The New 52
Grunge makes his debut in The Culling story line as one of the teen agents of the N.O.W.H.E.R.E. organization. He is tasked with killing Superboy after he rebels against the organization and aids the Teen Titans in helping rescue other captive metahuman teens. Grunge is defeated after Superboy uses his tactile telekinesis to rip several cybernetic implants out of his body.
Powers and Abilities
Grunge's foremost ability is his "sponging". Previously (before the Worldstorm soft-reboot), his powers were limited to taking on the characteristics of an object he touched (if he touched rock, he would become as hard as rock and gain super strength). In his latest, post-reboot appearances, the scope of Grunge's powers have widened. Now he is able to gain the superpowers of another super being for a short while. He has temporarily gained the wings of the Authori-teen's Nestling, the super strength and flight of the Authority's Apollo, and the super strength of Caitlin Fairchild. Incidentally, he also took on Fairchild's Gen-based breasts.
During the New 52, Grunge has been upgraded by having cybernetic implants placed inside his body. The implants allow him to transform and take on the characteristics of different objects without having to touch them.
In addition to his superpowers, Grunge is a skilled martial artist, has incredible intelligence, and a photographic memory.
In Other Media
Grunge appeared as a main character in the Gen13 animated movie. He is voiced by Flea. Grunge's powers manifested when he saw Freefall being tortured by Threshold.