Thurman is of a sapient spacefaring species native to Zaddlebrok-475. They have elongated slug-like bodies with four tridactyl arms, three eyes and are entirely covered in slime. They are identified as one of the 106 races that have sent representatives for peaceful contact to "the Dark Planet" (i.e. Earth) which never returned, due to being captured and held captive in Area 51. They are shown to survive on Earth's environmental conditions with no problems.