Jennifer Walters is the small, somewhat shy cousin of Bruce Banner (aka the Incredible Hulk) and the daughter of Los Angeles County Sheriff William Morris Walters. Agents of crime boss Nicholas Trask, who had crossed paths with her father, shot and seriously wounded her on a day when Banner happened to be visiting. Since there were no donors with her blood type available, Banner provided blood for a transfusion; although his radioactive blood transformed Jennifer into the green-skinned She-Hulk when the mobsters tried to finish her off at the hospital.
As She-Hulk, Jennifer possessed powers similar to those of her cousin, but at a reduced level. She also possessed a less monstrous appearance and was also never prone to the type of rage-induced rampages of her famous cousin. Although initially, her transformations to She-Hulk were triggered by anger, Jennifer eventually gained control of her transformation when Michael Morbius cured her of a lethal blood disease.
Eventually, Jennifer decided that she is going to remain in her She-Hulk form permanently - preferring the freedom, confidence, and assertiveness that it gave her compared to her more timorous and fragile "normal" form. After a brief solo career, She-Hulk joined The Avengers and participated in the Secret Wars - sparking her long standing rivalry with the newly empowered Titania. Following Secret Wars, she temporarily replaced the Thing as a member of the Fantastic Four.
During her tenure with the F. F., the She-Hulk was instrumental in preventing a radiation leak aboard the downed S.H.I.E.L.D. Helicarrier. However the radiation exposure had a drastic effect on Jennifer: she could now no longer transform back into her original form. However, this was an agreeable turn of events for her since she preferred being She-Hulk anyway, but it was revealed much later that her inability to transform was purely psychological.
Trivia: Although The Savage She-Hulk # 1 is cover dated February 1980, its Christmas holiday-themed advertising makes it clear that it was released late in 1979. Therefore, the She-Hulk is perhaps the last major creation of Stan Lee during his most prolific and critically acclaimed period, the 1960s and '70s.