Assistant to Dr. Connors (Before he became the Lizard) they worked on a project for SHIELD that involved experimentation of dinosaur tissue provided by a Savage Land native, Ka-Zar. Vincent soon became obsessed with the experiments on the lizard tissues and decided to steal the experiments. He quickly fled to the Savageland to further his experiments in the way he wished. He soon created a formula in which he drank turning him into "Dinosaur Man". Ka-Zar soon seeks aid of Spiderman to find and capture Stegron who has completely transformed into a reptile and rules over entities called the Swamp men. In an attempt to escape, Stegron uses the Swamp men to delay Spiderman and Ka-Zar while he leaves with a few other dinosaurs on a flying Ark and makes his way to New York to conquer the world.

Soon enough Black Panther and Spiderman catch up to setrgon who has already marched dinosaurs down Broadway. He engages Spiderman and Black panther only to be defeated and in an attempt to flee on a pterodactyl, he is knocked into the water by Spiderman and sinks quickly. He quickly reduces his metabolism where he is able to drift to shore. he returns to Manhattan where he searches for Curtis Connors and forces Connors to work for him as he keeps his son as a hostage. Through Dr. Connors, he creates a ray that reanimates the dinosaur skeletons at the Natural History museum. Through the stress and strain of the kidnapping of his son, Connors creates himself a formulas which turns him into Lizard man to combat Stegron. To Stegron's misfortune to plan his coarse of action in the cold winter of December, he succumbs to the cold weather and falls beneath the ice of a Central Park Lake and vanishes.

Stegron survives the misfortune and changes back into his human form where he lives in the Central park as a homeless resident. Another misfortunate event affects Stegron as he is blasted in Central park by a villain named Vulture. This blast contained nuclear energy which mutates Stegron back to his Dinosaur Man form. he attempts to steal Vultures Nuclear Blaster and follow through his original plan of the Dinosaurs within the museum but finds himself caught in a battle Spiderman and all of his deadliest foes where he is blasted by a villain named Strikeback.

Stegron soon gets more annoyed and feral due to his residency in New York and attempts to leave to return to his home, the Savageland. He hides within a supply ship bound for Antarctica, but finds himself within a SHIELD observation post where he starts to go on a killing spree murdering scientists. Black panther, Black Widow and Thunderstrike answers a distress call from the SHIELD post. Thunderstrike and Black Panther finds a way to release him out of the observation post and into the wild where he tries to reach the savage land but is beaten by the cold weather of the Antarctic. He falls under a deep state of hibernation within a massive Glacier but awakens to finally return home in time to join a battle between Spider-Man, Ka-Zar, Shanna the She-Devil, and the Roxxon Oil Company. He joins the Oil Company’s side in the battle but things start to get worse as the Hulk and Chtylok the Che-k'n Kau arrive. He decides to fight with the good guys to save him from a horrible fate and after the battle, he vows to become everyone's enemy.