Dr. Robert Crane and his assistant Chuck Grayson worked for years on perfecting a mechanical body that could sustain a human brain after the human body was unable to continue supporting the brain. Criminals found out about Crane's experiment thinking that it could provide a form of immortality and that people would be willing to pay high prices for the highly articulate mobile "iron lung" they tried to steal it and then tried to force Crane to tell them how to operate the robot. Crane refused and attempted to escape. The gangsters shot Crane in order to stop him from turning them in. Seeing their plans ruined the crooks fled leaving Crane to die. The robot was so heavy that they could not take it with them and without the knowledge to make it work they could not sell it. Seeing that Crane was about to expire completely, Grayson transplanted Crane's brain into the robot body successfully. Robotman let the world believe that Crane was dead and adopted the human alias of Paul Dennis.
Grayson testified at Robotman's trial, which was to determine if he were human or property. He revealed to the courtroom (including Crane's fiancee) that Robotman was, in fact, his old friend Robert Crane.
During the War, Grayson was a member of Project M, a special program specializing in psychological warfare. During May, 1942, Grayson meets with the Young All-Stars to help analyze Fury in an effort to rid herself of Tisiphone's influence.
Some time in the 1950s, Robotman disappeared. Unknown to Grayson (and the rest of the world), Robotman had been buried alive by a criminal named Lashky. Robotman went into an emergency suspended animation mode, preserving his human brain. Sometime later, Grayson died. Believing that Robotman would return some day, Grayson had his body frozen to donate it to Crane.
Just before the current age of heroes, Robotman was freed and reactivated, and he captured Lashky, now an old man. Then he learned about Grayson's frozen body, and he chose to live for a few years as full human rather than potentially forever inside his mental shell. Robotman's brain was then transplanted into Chuck Grayson's body and Dr. Crane started his new life as a human being.
- Genius Level Intellect, as he, with Crane, developed a successful method of transplanting a human brain into a robot body in 1941.
- Although this character was originally introduced during DC's Earth-Two era of publication, their existence following the events of the 1985–86 limited series Crisis on Infinite Earths remains intact. However, some elements of the character's Pre-Crisis history may have been altered or removed for Post-Crisis New Earth continuity, and no longer apply.
- In pre-Crisis continuity, Chuck Grayson was a native of Earth-Two who migrated to Earth-One (along with Robotman) for unknown reasons, some time before Robotman's encounter with Lashky. In New Earth continuity, this dimension-hopping did not happen.
- In pre-Crisis continuity, Chuck Grayson was a distant cousin of the Robin of Earth-Two. Post-Crisis, it was never established if Chuck was related to the New Earth Robin or not.
- 34 Appearances of Charles Grayson (New Earth)
- 4 Images featuring Charles Grayson (New Earth)
- Quotations by or about Charles Grayson (New Earth)
- Character Gallery: Charles Grayson (New Earth)