Vincent Stegron was a S.H.I.E.L.D. agent who worked with Curt Connors on the study of dinosaur DNA from the Savage Land. Ambition and curiosity got the better of him, and Vincent underwent a radical change to become the villain, Stegron.

Created by Len Wein and Gil Kane, his story began in Marvel Team-Up #19 (March 1974). After Connors’ experiment turned him into the Lizard, Stegron decided to do his own procedure by stealing and injecting dinosaur DNA into himself. He was turned into a reptile creature with Stegosaurus-like spikes, sharp claws and teeth, and a spiked tail. He also gained superstrength, enhanced durability and reflexes, ability to control other dinosaurs, and power to drain life force through physical contact.

Once he was transformed, Stegron planned to use his powers to take over the world and turn all humans into creatures like himself. He took a bunch of dinosaurs from the Savege Land to New York City where his crew fought Spider-Man, Black Panther, and Ka-Zar. Though the fight ended with Stegron apparently dead, he reappeared after a few months to force Connors into reviving dinosaurs at a museum. In the process, Connors turned back into Lizard and the pair fought until Spider-Man showed up and ended the skirmish.

Returning to the Savage Land, he took over a S.H.I.E.L.D. facility and engaged in a battle with Black Widow, Black Panther, and Thunderstrike. When Roxxon Oil started to illegally drill in the Savage Land, Stegron opposed the work and fought with Ka-Zar and others. The Hulk joined Stegron’s cause and other heroes followed when they realized that he just wanted to protect the Savage Land. They were successful and Roxxon left.

Stegron traveled to the Arctic Circle and found the Rock of Life, which has the power to de-evolve beings. He sent the Rock to New York and convinced a friend to put it on display at the Museum of Natural History, expecting it to turn people into prehistoric animals. Instead, it had a dramatic impact on both heroes and villains connected to the animal kingdom, meaning that Spidey, Vulture, Black Cat, Lizard, Man-Wolf, and others became more savage. Spider-Man fought against the change, reaching out to Mister Fantastic and the Invisible Woman, who helped him move the Rock to a vault in the Baxter Building and defeated Stegron.

When Moon-Boy was kidnapped by S.H.I.E.L.D., Stegron helped Devil Dinosaur by creating an army of reanimated dinosaurs to attack military bases. Later, he and Sauron cooked up a plan to turn humans into dinosaurs (again!), but they were opposed by Spider-Man and mutants who attended the Jean Grey School for Higher Learning. Stegron was kidnapped, along with other animal-based characters like King Cobra, Vulture, Scorpion, Rhino, and Tarantula, to be hunted by Kraven. The group survived and decided to stick together as the Savage Six.