Without him, all of you would be lost souls roamin
Jennifer Walters is a shy, reserved SHIELD engineer. Basically, after Banner is "executed", SHIELD hires Jennifer to start experimenting with his DNA. She tries to reengineer his DNA as a new Super Soldier Serum. In her experiments she learns how the Hulk serum bring out your repressed side. Out of morbid curiosity, she uses the serum on herself. She turns into funloving green skin dynamo. Like Banner, the stuff binds to her DNA. SHIELD decides to bring her on to the Ultimates (possibly).