A gangster wearing a mask.[1]

A mask is commonly worn by both superheroes and supervillains. It is typically used to hide one's secret identity. Not all superheroes with secret identities do wear masks though, for example, Superman doesn't wear a mask, instead, when he's playing Clark Kent, he uses his glasses, bad posture, and a bumbling personality to fool people into believing that he couldn't possibly be Superman.

References

  1. As seen in Billion Dollar Limited, which was set on Earth-2A.
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