Delilah "Dee Dee" Dearborn was a student at Empire State University. While monitoring a surge in the University's new experimental Particle Accelerator, she was stuck by a power surge from the machine. Time passed and she began to have nightmares of changing into a huge monster-like green creature, killing and tearing women apart.
Meanwhile, in the same area where she lives, women have turned up dead, two killed each month, all killed late at night. When the women bodies were examined there were traces of gamma radiation and parts of one woman were sewn to another. Doc Samson was called as a consultant to work with NYPD Detective Sharps in locating the gamma creature and She-Hulk was also called to handle the more "Super Hero" side of the project, confronting and fighting the gamma creature.
Soon after, both discovered and fought two different gamma monsters, similar in appearance, both believing that there's was the killer, but Samson discovered his to not be the killer. As She-Hulk was beaten and drained of her power, it was now obvious that She-Hulk has found the killer. The killer left She-Hulk, stating he already had two women for that month.
Samson took his Gamma creature to a cell and watched it as it slowly copied his gamma power, "Like a Geiger" Samson said. She changed, not back to her original (completely human) form but instead a more "female Samson" look. They teamed up and searched for the real killer, knowing he would be on the hunt for another girl. After trial and error. they were finally able to defeat the killer known as Patchwork.
Gamma Power Mimicry: Due to a Gamma radiation accident, Geiger has the ability to mimic the powers of any gamma-powered beings in her proximity, shown to be miles away and maintaining them for hours, potentially making her as strong as the Hulk, as intelligent as the Leader, etc. If she is around two gammas mutates, she will mimic the one with stronger gamma readings and/or personality. She can read and retain the memories of other gamma mutates or at least those she has already mimicked. Through training she can focus on one specific being and generally carries a lock of Doc Samson's hair so she can maintain his abilities as her own.
Base Level is Class 75 (70 tons) with Doc Samson's hair.
Personality Overload: She has little control over her powers, a downside exacerbated by the fact that she also takes on personality aspects of whoever she is mimicking as well. So if she mimics a villain she herself could become a villain. At one time she was able to focus on one gamma powered being for she would not become another, this took much effort on her part and left her momentarily helpless as she focused.
At least in the past, she lost consciousness via post-hypnotic suggestion upon hearing the words: "Freudian Slippers".