Natalia Alianovna “Natasha” Romanoff, also known as Black Widow, was one of the most talented spies and assassins in the entire world and a founding member of the Avengers.

For the most part, she was a level-headed, strong-willed and independent woman. Romanoff normally maintained a controlled, almost emotionless persona to keep whatever she was thinking a secret unless she was around people she absolutely trusts.Though a very serious agent, Romanoff was by no means stuffy and has a sarcastic sense of humor. [source]