Todd Arliss was once a professional swimmer, until he injured his back while rescuing a man who had fallen overboard from a pirate craft. Todd Arlis was told by the medic he could no longer swim. Dr. Lemuel Dorcas promised Arliss he could help. Dorcas would use the "morphotron" to imprint the genetic pattern of an animal onto a human. He would use tiger sharks on Arlis, but when he tried it, Dorcas also captured Namor's genetic pattern as well as the tiger shark's, transforming Todd into a super human. Dorcas then gave Tiger Shark the costume and the name, who then tried to use him for his own ambitious ideas. However, the Shark escaped to the open sea, and accompanied Lady Dorma down to Atlantis. Shark bullied himself to the throne, until Namor arrived and took it back, sending Tiger Shark to prison. But Tiger Shark escaped when Atlantis fell victim to the Serpent Crown, he swam to Sargasso Sea.

Tiger Shark again appeared as Namor's enemy when he stole the "Horn of Gabriel" which gave him the ability to summon massive monsters form the deep sea. Tiger Shark is later defeated by the combined forces of Namor and the Mighty Avengers.

Tiger Shark is later seen as a prisoner in Al Kraven's zoo of animal themed superheroes.

Tiger Shark has been seen fluctuating between his human and sharklike humanoid forms recently, depending on whether the ariter and artist have done their research properly. Continuity? What's that?