Dubbilex has the appearance of a tall, slender man with blue skin. His head is radically different from that of a human, most notably in the presence of horns and absence of a nose. He also has pointed, fin-like ears, and two ribbons of flesh, originating on his cheeks. He wears plain white hospital-like pants and a matching shirt.
Dubbilex is a G-Goblin, bred to possess telekinetic powers, but he also possesses psychic/telepathic powers that he has kept hidden from Cadmus officials. He appears to have some level of seniority in Cadmus. Dubbilex felt that Superboy was the hope for the genomorphs. As a genomorph hero, Superboy could "blaze a trail" for all genomorphs to be free.
Dubbilex started a fire in Cadmus's ground-level facility to attract attention to Cadmus. When Robin, Aqualad and Kid Flash arrived, he lured them into the underground labs by allowing Aqualad to see him entering an express elevator. When Guardian investigated the presence of the three sidekicks, he tried (but failed) to have Guardian leave his G-Gnome behind. After the young heroes were captured, he telepathically woke them up so that they could converse with Superboy, then telepathically guided Superboy when the four of them were trying to escape.
He finally revealed the part he played by stepping in to prevent the young heroes' capture by Guardian, the G-Gnomes and the other genomorphs at Cadmus. He stepped aside when Mark Desmond administered the Blockbuster formula to himself.
After Blockbuster's defeat, Dubbilex continued working for Guardian's "kinder, gentler Cadmus". However, he would continue his plans to obtain freedom for all genomorphs. He did so by secreting them away to a secret city deep under Cadmus, Genomorph City.
When Superboy returned to Cadmus looking for another super-clone, Dubbilex was at first convinced there was none. But when "Match" was found, Dubbilex was certain he had to be saved as well. From other genomorphs, he learned that Match was an older project that no human in Cadmus knew about. After Superboy was defeated in combat, Dubbilex telepathically overpowered Match and had him brought to Genomorph City.
Dubbilex welcomed Superboy into the sanctuary. However, Superboy's shield container contained a tracking chip, alerting Cadmus officials to the city location. Dubbilex's plans of autonomy were over.
During the Light's raid on Cadmus, Dubbilex was shown lying on the ground, unconscious.
Dubbilex and the Genomorphs were liberated from Cadmus by Superboy and his allies, and taken to a new land. Geranium City was build on that land, with Dubbilex serving as mayor under the name "Dabney Donovan", using his telepathy to disguise the city in the presence of outsiders.
Telekinesis: When Dubbilex uses his telekinesis his eyes and horns glow light red. He was shown to be able to lift medium-sized objects but claimed that he was incapable of opening the door to Project Kr.
Telepathy: Similar to when he uses his telekinesis, Dubbilex's horns glow when he uses his telepathy. His telepathic ability seems to be on par with the G-Gnomes. Telepathy was not part of his design, and he kept it secret from his superiors.
Dubbilex, like Guardian or Darkseid, is a Fourth World Character created by Jack Kirby. By long-standing practice DC almost always gives creator credits for Kirby's Fourth World characters similar to the creator credits listed for Superman, Batman, and Wonder Woman.
The fact that Dubbilex is responsible for Superboy's freedom may be a nod to the fact that for a very long period in the comics, Dubbilex had a close friendship with Superboy acting as a mentor and father-figure during the time that Superboy lived in Hawaii and at Project Cadmus. In the Young Justice comics, Dubbilex even attended the parent/teacher functions that Red Tornado held so as to keep the adults appraised of the team's wellbeing and behavior.