Natasha Romanoff/Black Widow

Black Widow (Natasha Romanoff) is a member of S.H.I.E.L.D. and The Avengers.

Iron Man 2
Natasha became the new assistant for Tony Stark, who, on the day she arrived, told her to go into the boxing ring while he'd Googled her finding out that she could speak french, Russian and Latin. While she was still in the ring, Happy Hogan teased about punching her but she tackled him to the ground. She then assisted Tony while he was in Monaco. She attended Tony's birthday party and flirted with him and he started to get suspicious about where she had come from.

She appeared with Nick Fury when he talked to him in Randy's Donuts, Tony was shocked when he saw her in a S.H.I.E.L.D. uniform, Fury revealed her true name and she gave Tony a serum. Natasha along with Fury and Phil Coulson went to Tony's house and she was told by Fury that she will stay acting as an assistant. Even after Tony learned that Romanoff was a S.H.I.E.L.D. agent, she stayed on as his assistant more to keep a eye on him than anything. Later at Stark Industries while Tony was visiting Pepper Potts, Natasha came in and requested for Potts to sign something. When Potts left, Tony started to grill Natasha and tells her that he finds it amazing that she does what she does. Tony claims she could not speak other languages, Natasha replies in Latin, then repeating herself in English telling him that he can "either get or be collected."

Natasha was attending the Stark Expo show, when Ivan Vanko took control of Hammer's Drones. Natasha ran out and found Happy Hogan and told him to drive the car to get her to Hammer Industries. After changing into a S.H.I.E.L.D. uniform during the drive, she broke into Hammer Industries to stop the drones. She encountered and took out several security men. Using technology at Hammer Industries, she managed to get control over War Machine's suit.

The Avengers
Even in her short career at S.H.I.E.L.D., agent Natasha Romanoff a.k.a Black Widow has turned covert espionage into an art form. Armed with an extensive complement of "widow stings" and cluster bombs, as well as a vast repertoire of martial arts and wushu training, Romanoff's skill-set seems to know no bounds.

Natasha was tied to a chair by Georgi Luchkov and appeared to be being interrogated when in fact she was the one interrogating him. Phil Coulson calls and tells her that Agent Barton has been compromised so she breaks free from her restraints and knocks out Luchkov's henchmen before being sent to collect Bruce Banner. Natasha pays a child to act like her father is sick and leads Banner to a shack on the outskirts of the town. Natasha approaches Bruce and tells him that he needs to help them. After Bruce agreed, she introduced him to Steve Rogers, a.k.a "Captain America".

Once Loki is captured, Natasha talks to him in his holding cell and he taunts her claiming that he will make Clint kill her. He lets slip that the "monster" is already on board of the helicarrier and she works out that he plans to use the Hulk so Romanoff warns Director Fury. Loki summons some guards, including Hawkeye, to the helicarrier and Hawkeye uses an explosive arrow to destroy one of the four engines. Natasha and Bruce are thrown through a window by an explosion and Bruce loses control and changes into the Hulk despite Natasha's attempts to keep him focused. She manages to get her leg free from the debris that was on top of her and begins to run because the Hulk is attacking her. He easily catches her and knocks into a wall. Fury asks someone to stop Hawkeye and she volunteers, finding him and knocking him unconsious. She then visits him in the recovery room where he is free from Loki's spell, wanting to take action against the God of Mischief.

Natasha, Clint and Steve seek Loki, who releases his army so the Avengers are forced to assemble and battle the onslaught of alien invaders. She fights alongside Steve and Clint. When the others arrive she takes one of the Chitauri's aircrafts and heads to the top of Stark Tower where the portal is open. She talks to Erik Selvig and uses Loki's staff to close the portal. The team regroup and send Loki back to Asgard with Thor and then they go their separate ways.