Character concept: Natalia “Natasha” Alianovna Romanova is the first character to take on the Black Widow codename in the modern mainstream Marvel Comics. She was created by editor and plotter Stan Lee, scripter Don Rico and artist Don Heck, and first appeared in Tales of Suspense #52 (April 1964). The character has been associated with several superhero teams in the Marvel Universe, including The Avengers, The Defenders, S.H.I.E.L.D., and the Thunderbolts. She has appeared in many other forms of media, including the major motion picture Iron Man 2, where she was portrayed by actress Scarlett Johansson.
And this is how she looked during Iron Man 2 when she was introduced as the character.