Natalia Romanova (Earth-4026)

"Alright, listen up little spider, when I'm done with you, you'll be able to kick two people in the face in a mid-air split, paralyze someone with your left pinky toe, and choke a man with your thighs. In heels."

- Black Widow

Natasha Romanoff is a former assassin turned hero who uses her abilities to fight with the Avengers.

Trivia

 * She and Clint often use the old fallback of "Clint is deaf and Natasha doesn't speak English" in compromising situations.