Wikipedia:
In Iron Man 3, AIM is using a formula based on plant research to give people superpowers. In the comics, Man-Thing was originally a scientist who was doing top secret research on plants in the Everglades when his wife betrayed him to AIM. In desperation, he injected himself with his untested formula, only to discover it had seriously unexpected consequences. The female AIM agent (played by Stephanie Szostak) who battles Tony to the death midway through the film is named Ellen Brandt, who is Man-Thing's treacherous wife. The character even has the scar on her face she received fighting Man-Thing in the comics.