Grunhilda (portrayed by Miriam Margolyes) was a pixie who served as the nanny to Princess Elena, a changeling child who had been 'implanted' with a Sidhe when she was an infant, knowing that Elena's father, Lord Godwyn, would eventually seek to strengthen the ties between his kingdom and Camelot with a marriage between Elena and Arthur, and seeking to place a Sidhe queen on Camelot's throne. Grunhilda's true nature was uncovered by Merlin and Gaius, Merlin subsequently destroying Grunhilda in a duel—although she was able to take an exceptional amount of damage from Merlin's staff, (the staff he had kept from "The Gates of Avalon",) before dying—while Gaius prepared a potion to expel the Sidhe from Elena. Grunhilda developed a 'liking' for Gaius, to his and Merlin's disgust. Gaius tried to avoid her romance as much as possible. He fought her as short fat and grubby. When they made a potion for Elena they had to use Gaius as bait to keep Grunhilda away from her so then they could give Elena the potion without Grunhilda seeing.