Prince Arthur Pendragon slew one such spider before escaping a horde of them in his attempt to procure the leaves of the Mortaeus flower to save Merlin from dying from its deadly petal. The spiders were said to be deadly by Nimueh, who left Arthur hanging unto a ledge for the creatures to finish off. After he slew the first one, hundreds more came after him, and would have killed him if not for the guiding light sent by Merlin in his subconsciousness (The Poisoned Chalice).