Tiger Shark

A champion Olympic swimmer, Todd Arliss earned nearly half million dollars in advances for public exhibitions, but his dreams came crashing down around him when he injured his back and legs while rescuing a man who had fallen overboard from a private craft. He was told that he would never be able to swim again, so he spent his fortune in seeking any kind of medical help. Dr. Lemuel Dorcas promised Arliss he could help, and, despite the pleas of his sister, Diane, Todd agreed. As part of the process, Dorcas hoped to use his "morphotron," which could imprint the genetic pattern of an animal onto a human. In seeking tiger sharks to use on Todd Arliss, Dorcas accidentally captured the Sub-Mariner as well, and Namor’s genetic pattern was transformed as well as the sharks’, transforming Todd into a superhuman, amphibious creature.

Dorcas, a criminally-motivated marine biologist, gave Todd the costume and codename of Tiger Shark, hoping to use him in his own criminal ambitions. Tiger Shark, however, had other ideas. Even though he was weak from the morphotron, he bested the Sub-Mariner and escaped for the open sea. Happening upon the Sub-Mariner's betrothed, the Lady Dorma, the Shark accompanied her to Atlantis, where he bullied his way into gaining the throne until Namor arrived and recaptured it, imprisoning Tiger Shark with the hopes of returning him to normal.

Tiger Shark escaped when Atlantis fell victim to the Serpent Crown and swam to the Sargasso Sea. There, he encountered the Mist-Men of Sargasso, a band of sailors and seamen from various cultures and time periods who were immortal prisoners of the area. Tiger Shark offered to lead them out of the area if they would serve him once they were free. The Sub-Mariner, however, found the mist-locked area and opposed the Shark once more. Tiger Shark escaped in the wake of the explosion of an experimental Nazi torpedo. Not long after, Tiger Shark again crossed paths with the Lady Dorma, who agreed to marry him if he would help save Atlantis from Orka, another of Dr. Dorcas's creations, and the Atlantean traitor Krang. The Shark fought valiantly against Orka and his battalion of killer whales. Locked in battle, both Tiger Shark and Orka were sucked under when a huge crevice opened in the ocean floor.

Eventually escaping, Tiger Shark discovered that his amphibious powers were diminishing. Hoping to capture Namor to recharge his powers, he first sought out Dr. Dorcas, but allied with the Lemurian empress Llyra and the scientist Lymondo. Llyra wished vengeance upon Namor for thwarting her ascent to the Atlantean throne. Tiger Shark wanted to use Lymondo's replica of the morphotron to siphon more of Namor's power into himself. Their first attempt to kidnap the Sub-Mariner failed when they kidnapped his ally, the Human Torch, sending their vessel to the sea bottom. Next, the three learned of and kidnapped the Sub-Mariner's human father, Leonard McKenzie. Namor of course came to the rescue and was captured, placed into the morphotron and used to restore Tiger Shark's prowess. Stingray also appeared, and in the ensuing struggle, Tiger Shark threw a lead pipe at Namor's father, killing him and providing the opportunity to escape.