Born into a wealthy family of eccentric philanthropists, Samantha Parrington grew into an idealistic feminist. When her parents adopted the monstrous Hulk as their latest pet cause, Samantha formed a rapport with the misunderstood brute and helped talk him down from the Statue of Liberty, though her father took all the credit for this feat in the media. Miffed, Sam led her women's group in an anti-patriarchal protest that attracted the attention of Hulk's enemy, Enchantress. Amora magically transformed Samantha into a raging, man-hating facsimile of the Asgardian warrior goddess Brunnhilde the Valkyrie, whose form and might Amora could replicate at will, having trapped Brunnhilde's soul in a mystical crystal centuries earlier. As the ersatz Valkyrie, Samantha battled the Hulk to a standstill until the spell wore off, returning her to normal just as Hulk reverted to his human form of Bruce Banner. The confused pair parted awkwardly, neither fully recalling their battle, with Samantha half-convinced it was all a dream.
Brunnhilde was later reborn in the mortal host body of Barbara Norriss and, as the Valkyrie, became a mainstay of the Defenders. She went on to become the longest-serving member of that group, remaining with them even after regaining her original Asgardian body; however, she gradually felt more detached from life on Earth. During a period when the Defenders were disbanded, Brunnhilde returned to Asgard and resumed her ancient duties as leader of the Valkyrior, but Earth had not seen the last of the Valkyrie. When the rogue god Pluto sought a Valkyrie pawn, he had Amora's sister Lorelei transform Samantha Parrington into the Valkyrie again. A mind-controlled Samantha served them until they ran afoul of the reunited Defenders and Brunnhilde, who routed Pluto and Lorelei after Samantha shook off their control. Happy to have a worthy successor on Earth, Brunnhilde returned to Asgard and Samantha joined the Defenders as their new Valkyrie. Her parents have tried to support her new superheroic pursuits by offering the Defenders funding, equipment and well-intentioned meddling.
Brunnhilde, sadly, was among the many slain during a recent Asgardian revolt staged by Loki in fulfillment of the Ragnarok prophecies; but her proud heroic legacy lives on through Samantha Parrington.