Marvel Universe Hulk
Doctor Alec Holland was a leading scientist in the field of bio-restoratives using plant life. He was recruited by Cobra and worked alongside Doctor Mindbender believing they were working on a formula to help the world, while really Mindbender was trying to improve his Bio-Viper formula. When Holland found out he tried to escape and there was a struggle. He was spalshed with a combination bio-restorative and bio-viper chemicals. Mindbender escaped and the lab exploded. Holland ran out of the building on fire and into the swamp, where days later he emerged as the Swamp Thing.