Prior to his t-shirt designing career, Tunic Shirt had been a wealthy playboy. After accidentally falling off of his cruise ship he had been stranded on Starfish Island, where he learned to print shirts by any means necessary using a make-shift silkscreen. He developed primitive Troll Prints as advanced methods of hunting and foraging for food, then assembled a green 3XL t-shirt for camouflage. Eventually a commercial freighter stopped by the island, and he swam out thinking they might rescue him. They were in the middle of a mutiny and he had to liberate the crew from dangerous pirates. Making a small t-shirt ninja mask to hide his face from sight, he took them all down using the skills he had developed. Now calling himself Green Tunic, he realized that he could use his abilities to serve society for the greater good and fight crime.