The Talking Worm was the last remaining guardian of the Order of the Witches of the Sand, having protected their secret chamber for generations.
He is a small ordinary-looking yellow sandworm with a human-like mouth. To mask his mundane appearance, he hides behind an imposing mask with a horn.
Aside from his unusual ability to talk, he is apparently immortal or very long lived, having guarded the chamber of the witches for centuries. Whether these traits are because of the witches' magic or a natural part of his species is unknown, but considering that he implies that his mother is still alive, sandworms may be naturally capable of speech and long life.
His origins are unknown, but at one point a thousand years ago, he was made the caretaker of the tower the Witches of the Sand resided in before it sank into the sands and the witches themselves perished. The worm was completely ignorant of their fate but continued to faithfully guard their secret chamber for generations.
Upon discovering from Sadira that the witches had died out centuries ago, he was quick to leave his position, angry at the fact that he had been forced to guard their temple for them for no reason all these years and decided to move back in with his mother.