When J. Jonah Jameson first hired Peter Parker,he was very keen to learn how Peter took such amazing photographs of Spider-Man. He hired private investigator Mac Gargan to follow Peter around all day so he could find his answers. However Jameson’s attention was soon swayed when he saw an article about a scientist claiming to find a way to cause artificial mutations in animals. At first considering it to be the work of a crack-pot, Jameson soon became interested when he thought how this might benefit him getting rid of Spider-Man. When Gargan next came to Jameson to report on Parker’s activities, Jameson told him of the new scheme he had planned.

Rushing immediately to Dr. Stillwell’s lab, Jameson told the ambitious scientist that he would pay $10, 000 if he could perform his experiment on a human, in this case Mac Gargan. At first reluctant, Dr. Stillwell couldn’t say no to such a donation and proceeded with the experiment. He decided to give Gargan the powers of a scorpion but wasn’t sure of the side-effects that this would have on his brain. Nevertheless, Gargan drank the serum and proceeded with the rest of the experiment. Dr. Stillwell also created a scorpion suit equipped with a powerful electro-mechanical tail. Gargan’s transformation was now complete.

However shortly after the experiment, Dr. Stillwell continued to do further tests and discovered that the experiment was not such a success. As Gargan increased in strength, he would eventually lose his sanity. Dr. Stillwell fashioned a serum that would cure his experimental subject of his powers and proceeded to find Gargan, who was busy battling Spider-Man. Arriving on the scene, Dr. Stillwell told Gargan of the side-effects of the experiment and told him about the cure. However, Gargan didn’t want to lose his power and climbed up the side of a building to get away. Dr. Stillwell proceeded to follow him but had lost his grip. As he fell, Dr. Stillwell threw the serum at Gargan in a vain hope to cure him. He missed and fell to his death.