Errol is a viking of the Knudsen clan. He 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. His name is not revealed in either the animated series, nor the books, but only on the character sheet for the clan.
Errol is a slender build man. He has a red beard and long red hair that cover his mouth and eyes respectively, leaving only his nose visible.
Not much is known about Errol's personality, other than that, like his fellow vikings, he wants the Medallion of Sigurd to get rid of his fear. The character sheet for the clan claims he is stealthy and silent.
When first seen, Errol, along with the rest of the 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.
Errol is seen participating in a battle twice; the first time his 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 Errol's fate unknown.