Red She-Hulk is a fairly recent Marvel villain and enemy to the Hulk - she is an 'evil'-version of She-Hulk in much the same way that Red Hulk is an 'evil'-version of the Hulk but like Red Hulk her powers work differently from She-Hulk in many ways and she has striking red skin rather than the traditional green skin of gamma-mutates.
Red She-Hulk, or Betty Ross/Banner, is traditionally a good character, but she has done some very questionable things in her life. Especially with regards to her husband Bruce and her father Thaddeus Ross. This female version of the Red Hulk first appeared when the Red Hulk had gathered a team of mercenaries (Thundra, Punisher, Electra, Crimson Dynamo and Deadpool) to hunt down Domino.
The Red Hulk's team of mercenaries, Code Red, found Domino in a seedy bar located in the heart of Hell's Kitchen. However, Domino had been waiting for them, and ambushed Code Red with her own team, X-Force. All the various team members paired off and began their individual battles, with Wolverine facing the Red Hulk. Wolverine slashed his Adamantium claws across the Red Hulk's face, blinding him until his healing factor restored his eye sight. Just as Wolverine was about to deliver a killing blow to the Red Hulk, Red She-Hulk appeared and blindsided him. She had protected her male counterpart long enough to challenge Wolverine.
The Red Hulk had no idea who had come to his aid, and Thundra was forced to explain that it was a female counterpart who looked just like him. While the Red She-Hulk and Wolverine battled, she proudly boasted that she had stolen Elektra's sai and Domino's automatic firearm from them after killing them. Enraged, Wolverine plunged his claws into a powerline and electrocuted them both. Having forced the Red She-Hulk away Wolverine went to search for Domino, but she pulled herself to her feet and lunged at him once more. When he stabbed the Red She-Hulk with is Adamantium claws, she distracted him by spitting some sort of acid-saliva onto his face.
The Punisher distracted Wolverine long enough for the Red She-Hulk to drag the Red-Hulk away from the fight. She dragged him down into the sewers to escape. Down there, the Red Hulk slowly followed her around while she evaded his questioning. There was a moment of awkward silence after he told the story of blind men & the elephant, and she screamed that the last person who told her that story was dead to her.
However, just as the Red Hulk began to trust the Red She-Hulk, she double crossed him, and plunged Elektra's stolen sai into his neck. The other members of Code Red (bar Elektra) were gathered in the sewers and awaiting the orders of Doc Samson.
She recently resumed her romantic relationship with her husband Bruce.