Originally, Urthwyte the Mighty was dubbed the White Ghost on Marlfox Island (prior to its occupation by the Marlfoxes) because of his white fur. However, he later left the island for Salamandastron, leaving behind the legend of the ghost. When the Marlfoxes took the island seasons later, the legend still remained.
Later, the White Ghost was said to haunt Castle Marl, but was really a clever trick thought up by one of Queen Silth's brood, Lantur, in an effort to scare the Queen. Lantur painted a white sheet with red and black to create the appearance of a blood stained ghost with a cavernous black hole for a mouth and eyes, maneuvering it with ropes from a loft in the High Queen's ceiling. Lantur, the "White Ghost," and her sidekick Wilce, the rat, succeeded in driving Silth insane. The voice of the ghost was made by Lantur or Wilce moaning through a cabinet that went through Silth's ceiling. The White Ghost has since retired.