Gunnhild is a viking of Knudsen clan. She appears in the season 2 episode "Chapter 4: The Eternal Warriors" and the tie-in novel "Hilda and the White Woff" . The character does not appear in the graphic novels. Her name is not revealed in either the animated series, nor the books, but only on the character sheet for the clan.
Gunnhild is a slender build woman with red hair, which she wears in a tail. She has red warpaint on her face and left arm.
Not much is known about Gunnhild's personality, other than that, like her fellow vikings, she wants the Medallion of Sigurd to get rid of her fear. According to the character sheet, she is the second in command of the clan, and currently single & not looking.
When first seen, Gunnhild, along with the rest of her clan, has been trapped in an endless fight against their rivals, Torgund's clan, over the medallion. Each night the two clans fight, after which the winners take the Medallion, and Sigurd secretly brings the defeated vikings back to life so they can reclaim the medallion.
Gunnhild is seen participating in a battle twice; the first time her clan has the medaillion, and due to the loss of fear they are too reckless to put up a smart fight and are all killed. The following day however, Sigurd revives them with a potion, which also restores their fear and erases their memories of the last battle. With their fear restored, the Knudsen fight much better the second time around and take the medallion from Torgund's clan. They are not seen again after this fight, leaving Gunnhild's fate unknown.