gamma mutation allows her to assume a secondary form with superhuman strength, endurance, leaping ability, resistance to all manner of physical impact and injury, and unstable gamma levels that can be redistributed as intense heat and nuclear force
Recruited during a membership drive held by the Wasp to find female members in Avengers (1st series) #221.
In Marvel Graphic Novel #18, She-Hulk lost the ability to transform back in Jen Walters. She would remain stable as She-Hulk for many years, although she underwent temporary changes in Sensational She-Hulk such as a weaker gray form or a stronger and more muscular savage green form. In Avengers (3rd series) #57-74, extended exposure to the presence of Jack of Hearts' zero radiation restored her ability to become Jen Walters.