Patsy Walker was created by Ruth Atkinson, and made her first appeared in Miss America Magazine #2 (Nov. 1944), published by Marvel precursor Timely Comics. Patsy was originally the star of a long-running teen romance series.
Later Patsy embarked on a new career in Amazing Adventures (vol. 2) #13 (July 1973). There, she met Hank McCoy, one of the original X-Men, in his alter ego as the Beast. She had become dissatisfied with her married life to Buzz Baxter, and after she aided the injured Beast, Patsy asked for a costume in return, “something with powers, or a serum, or anything”, now wanting to become a superheroine.
Shortly afterward, the Avengers, with Beast and Walker tagging along, invaded the complex of buildings belonging to the Brand Corporation. Now a subsidiary of Roxxon, a multinational conglomerate, Brand was also where Walker's estranged husband, an Air Force colonel, was posted. There they found one of superheroine Greer Grant's spare Cat costumes. Patsy Walker immediately donned the yellow cat-suit and dubbed herself "Hellcat" in The Avengers #144 (Feb. 1976).