Barbara "Bobbi" Morse, an accomplished scientist, spy, and superhero, adopted the alias of Mockingbird. Bobbi excelled academically and pursued a Ph.D. in biology under Dr. Wilma Calvin. Her journey into espionage began through her involvement in Project: Gladiator, a S.H.I.E.L.D.-backed initiative aimed at recreating the Super-Soldier Serum. Trained as a spy, Bobbi received the codename Agent 19 during this time.

Tasked with investigating suspicions surrounding Dr. Paul Allen's potential involvement with A.I.M., Bobbi became entangled in a series of events leading to the transformation of Theodore Sallis into the Man-Thing. Her adventures in the Savage Land with Paul Allen and subsequently with Ka-Zar led her through various conflicts and encounters, including facing off against Victorius in New York City.

As Huntress, Bobbi undertook a mission to investigate corruption within a Latin American S.H.I.E.L.D. branch before returning to her duties within the organization. Adopting the alias Mockingbird again, she embarked on missions that intersected with superheroes like Spider-Man during the Contest of Champions.

Her life took a significant turn when she crossed paths with Clint Barton, a.k.a. Hawkeye, during an investigation at Cross Technological Enterprises. Their collaboration led to defeating Crossfire but resulted in Hawkeye's hearing impairment due to the villain's ultrasound technology. Despite this, they eloped and joined forces as a crime-fighting couple, even co-founding the West Coast branch of the Avengers. The West Coast Avengers faced numerous adversaries, including Goliath, Graviton, and the Vision when he went rogue. Bobbi's adventures with the team took an unexpected turn when they were scattered across time by Kang the Conqueror, leading to a tumultuous encounter with the Phantom Rider. This encounter ultimately ended tragically, leading to a rupture in Bobbi and Hawkeye's relationship.

The rift between Bobbi and Hawkeye deepened further as Bobbi was embroiled in a plot involving the abduction of the Vision by world governments. Although they managed to restore the Vision, the incident strained relationships within the team, leading Bobbi to part ways and operate independently. Her life continued to be marked by significant events, including her imprisonment by the Skrulls, her involvement in the resistance against Hydra, and her relationships with individuals like Lance Hunter. Mockingbird's involvement in scientific endeavors alongside Nadia Van Dyne's Genius In action Research Labs began her commitment to helping young scientists.