The evil Scarlett Reynolds
Scarlett Reynolds (Sharon Lawrence) was the titular main villainess from "The Scarlett Getter," episode 7.06 of American Dad! (airdate November 27, 2011). She is a former CIA boot camp classmate of Stan Smith, and she was spotted at a coffee shop by Stan, who was with Roger (disguised as a Nigerian student).
Upon seeing Stan, Scarlett reveals that she left the CIA and works in the private sector, and it was at that moment that Stan (who still has a crush on Scarlett) invited her for dinner. Francine is instantly displeased over Stan's fawning over Scarlett, and while venting her feelings to Roger (who was already upset over Stan stating that he had no chance with Scarlett), she decides to send Roger to charm Scarlett as a dashing lover named Dan Andsome-Handsome. Scarlett is taken in by Roger in his persona and goes on a dinner date with him, and after Roger tells Stan that he plans to have sex with Scarlett in the ski cabin--similar to Stan's fantasy--Stan tells NFL legend-turned-alien hunter Shannon Sharpe about Roger's whereabouts.
Once Shannon and Stan arrive, Scarlett reveals her true villainous persona, beginning with shooting and killing Shannon after he outed her as an alien hunter. After tying up Stan, the evil Scarlett also revealed to Stan that she "found" him on purpose because she knew he had Roger (who Scarlett tortured before Shannon and Stan entered), while also insulting him and calling him a loser. The villainess stated to Stan that she would kill him due to him witnessing killing Shannon, prompting Stan to berate her and show his devotion to Francine, who later appeared and shot Scarlett. Scarlett later rolled into the fireplace and burned to death.