Dr. Vellian Crowler (4Kids dub) was the main antagonist for about the first half of the 1st season in Yu-Gi-Oh! GX. He hails from Italy and is the head professor of the Obelisk Blue dormitories. He does not want to rule the world or destroy the world, he just wants to expel Jaden Yuki, because the boy humiliated him in a duel. He hires a few of the toughest duelists to duel Judai and his friends. Some of the duelists are: Jun Manjoume, Judai's friend and greatest rival, a mercenary named Titan, the Paradox Brothers and a few others. Right around the 2nd half of season 1, he started to respect Jaden and helps Jaden save the Duelist Academia numerous amounts of times.

He was voiced by legendary voice actor Sean Schemmel.


His usual outfit consists of the a more regal variation on the standard Obelisk Blue uniform, complete with gold trimmings and ruffled pink collar, shoulders, upper chest, and sleeves. His blonde hair is sectioned in two layers, with the layer furthest from his face tightly-bound in a ponytail, and he also wears crescent-shaped earrings. He carries an Academy-issued Duel Disk known as a "Duel Coat," worn horizontally across his torso, which has a motion sensor that automatically ejects cards from his deck when he is ready to draw.


Cronos' main deck consist Ancient Gear monsters, which are Machine-Type monsters usually with Earth Attributes. They are known to overwhelm other duelist because most of them, when they attack, traps and spell cards can not be activated until the end of the damage step. His strongest monster is; the Ultimate Ancient Gear Golem.