Oblivion: We are the darkness... We are the unseen... WE ARE OBLIVION!
Turok (2008 reboot)
Anytime Mama Scarface appears. She doesn't show up often, but when she does, she steals the show...especially when you get to fight her!
Finishing her off in the final boss battle: You leap onto the side of her head, slam a knife above her eye, dangle from one hand while you chuck a grenade into her eyeball, and then fall off just before her head explodes.