Ruff is a basilisk who, as an egg, was given to Jason by Strife and Discord (disguised as the Babylonian Sibyl and translator. Though it was Strife who played the Sibyl) as a trick. After hatching, he immediately imprinted on Iolaus, who took to his role as 'mama' quite well. Iolaus was forced to release Ruff into the wild, though, after the little basilisk's venom turned out to be a fire hazard.
The two of them were briefly reunited an undetermined time later when Ruff, now fully grown, was found being held prisoner by a cruel traveling sideshow ringmaster. Iolaus, feeling that diplomacy would not fix things, smuggled Ruff out of his cage and into the woods. After a cat-and-mouse game with the ringmaster and his lackey, which (thankfully) ended with the arrest of the ringmaster, Ruff and Iolaus parted ways again.
- Can "shake hands" - 1.18 - A Serpent's Tooth, 1.23 - The Mysteries of Life.
- Can roll up into a ball - 1.18 - A Serpent's Tooth.
- Can play "fetch" - 1.18 - A Serpent's Tooth.
- Can spit a green goo venom that spontaneously bursts into flames - 1.18 - A Serpent's Tooth.
- Can breathe fire - 1.23 - The Mysteries of Life.