Gina (Michelle Monaghan) was a villainess from "Max Jets", episode 9.11 of American Dad!.
Gina was a gold digger who met Roger's elderly and rich persona Max Jets at the restaurant where she works as a waitress. The two began dating and eventually got married, despite the Smith family's protests that Gina just wants Max for his money.
At the wedding, Gina revealed that she signed a prenuptial agreement and the Smith family began to feel guilty about their accusations about Gina (as well as their various attempts to kill Max himself to claim his fortune). But soon after that, Max ate a piece of his wedding cake and died.
The Smiths later found out that Max left all of his money to his estranged son, Jerry Jets (another of Roger's personas). Jerry turns up at the reading of Max's will along with Gina, where it is revealed that Gina had been having an affair with Jerry behind Max's back and convinced Max to leave all of his money to Jerry. It is then revealed that the evil Gina poisoned the wedding cake that Max ate to kill him, and signed the prenup to deflect suspicions. She and Jerry walk off together with Max's fortune.
At the end of the episode, Roger shows up as himself and reveals to the Smiths that Gina was even more evil than he thought and that she ended up killing Jerry for his money by beating him to death with an oar. Everyone is confused by how Roger is still alive after seemingly dying twice, the episode ends with Roger saying he'd love to explain how, but he can't because there's no time.