Simon Stagg is a fictional character appearing in American comic books published by DC Comics, serving primarily as an antagonist to the superhero Metamorpho in most comic book stories and their adaptations. He is responsible for turning Rex Mason into Metamorpho out of spite after catching him in a relationship with his daughter Sapphire Stagg. Given his high status as a supervillain, he has also come into conflict with Batman, the Flash, Green Lantern and other heroes in the DC Universe.

Metamorpho is a superhero appearing in American comic books published by DC Comics. He was created in 1965 by writer Bob Haney and artist Ramona Fradon.