9. Shoreh Aghadashloo as Dina Araz on 24
The fourth season of 24 is notorious for its main storyline, which featured an American Muslim family that appeared assimilated on the surface, but was really a fully functioning terrorist sleeper cell planning an especially eventful day for L.A. and the nation overall. That's right, father, mother Dina, and son Behrooz were all in on the act.
That is until Behrooz actually got caught up in the faux assimilation, got himself a snow bunny, and started re-thinking that whole nuke the country shit. Even worse, the chick got jealous and followed Behrooz to one of the secret hideouts, although she was none the wiser. When Dina found out about the relatively minor indiscretion she promptly invited Behrooz's secret girlfriend over for tea with a side of cyanide, and then shot her for good measure to both eliminate the potential threat and rededicate him to the cause. And you thought your mom was disapproving.