For the first Superman movie, producers wanted Christopher Reeve to wear fake muscles under his suit but he refused. He instead went on an intense training program adding 30lbs of muscle to his thin 189lb frame. He got so big they had to reshoot earlier scenes as they didnt match later shots.
There was a comic book series chronicling an alternate Superman timeline where he lands in the Soviet Union instead of the United States.
George Reeves, the actor who played Superman in the 1950s was wary because some fans tried to test his “invulnerability.” At one appearance a young fan pulled a pistol on him. Reeves convinced him to hand over the gun by telling him that a bystander could be hurt when the bullets bounced off