Pixie is a member of the Eternals, a species diverted from humanity by experiments conducted by the Celestials one million years ago. It is unclear when she was born or how old she really is, though it has been stated she is young by Eternal standars. Pixie craved adventure and wished to become a hero, which led her out into the human world. She sought the Hipster and offered to become his sidekick, but he refused. She later met a young man with great strength, Oxbow, and decided he would become a hero and she would he his sidekick.
Soon after their hero career began they became a part of the First Line, the foremost superhuman team of the time. They soon became some of the team's mainstays, remaining through its many incarnations. Pixie fought alongside the First Line for many years, but she never revealed her true origin, except to Oxbow. When the hero Yankee Clipper returned from his time-travels, it was Pixie who helped him adjust to the world after his 20-year absence.
The First Line met their demise as they attempted to stop a Skrull invasion of Earth. Being one of the last Firstliners alive, Pixie was the one that detonated the entire fleet of invading aliens. As an Eternal, she survived the explosion and returned to Earth. It is unclear why, but Pixie stopped being a heroine and returned to Olympia, with the Eternals. She met with the Yankee Clipper, after another of his time-jumps, to explain him what happened to the First Line.
Years later, Pixie and the Inhumans stopped Yeti, who was battling the X-Men at the time, revealing that he was an Inhuman. Soon after, Pixie and Ikaris stopped Angel from finding the Deviants while on a mission against the Mole Man.
In the 22nd Century of Earth-700, Pixie warned Cassandra Locke's father about an upcoming Skrull invasion and helped him find a message from Cassandra hidden in the Apollo moon lander. She also claimed she had been fighting the Skrulls covertly for the last two centuries. Soon after she was arrested for sedition, accused by the Skrull Ambassador.
The whereabouts of present-day Pixie are unknown.