Xerxes is the familiar of the sorcerer, Mozenrath. He is a flying eel/lamprey-like creature, who can speak in broken English. He is endlessly loyal to his master, though he has the habit of saying the wrong thing and taking a beating for it.
Episodes Xerxes has appeared in:
The Citadel
The Secret Of Dagger Rock
Black Sand
Two To Tangle
The Wind Jackals of Mozenrath
The Lost City Of The Sun
The Book Of Khartoum
The Hunted
Vocal Hero