Magnus is a Viking on Berk who first appears in the episode We Are Family, Part 1. He is later seen as one of the patients 'Dr.' Gobber "heals" in Dragon Eye of the Beholder, Part 2, when he is attempting to replace Gothi while she was with the Dragon Riders looking for a Snow Wraith tooth.
Dragons: Riders of Berk
Magnus is only briefly seen in the beginning of the episode, carrying a sack of flower. Gobber greets and wishes him a happy Bork Week.
Dragons: Race to the Edge
Three years later, Magnus had a small dragon trap clamped on his leg, and is using his double-bladed axe as a crutch. Gobber throws what appears to be squid ink at his leg, and somehow his leg catches on fire. Gobber quickly douses the fire with water, which knocks Magnus out. Gobber drags him away, groaning, and then asks for the next patient in line to come see him.