Mirror Master - Sam Scudder

Sam Scudder was a simple convict, but had the goal to learn how to get inside the reflection of a mirror. Stumbling into a hall of mirrors, he experimented and discovered a way to get in his own reflection. He used this power to become the criminal Mirror Master. He battled the Flash several times. Scudder died around the same time as Barry Allen, alongside the Icicle during the Crisis on Infinite Earths. Later, Captain Boomerang briefly assumed Scudder's identity, becoming the second Mirror Master. He used this as an alternate identity with which to commit crimes, thus not alerting his teammates in Suicide Squad to his extracurricular activities. Pre-Crisis he studied mirrors after someone's reflection was held inside a mirror he was working on in the prison workshop. He then learned how to create creatures of light.

In Blackest Night crossover, Sam Scudder has reanimated as an undead Black Lantern during the Blackest Night and is preparing an attack on The Rogues with the deceased members who are also reanimated.

The Rogues visit Sam Scudder's old hideout and unveil a giant mirror with the words In Case of Flash: Break Glass. It has been shown in several past incidents that something lives in the mirror universe that is deadly. When the Flash enters the gateway of unveil a giant mirror, it only shows him a vision of his mother. The Rogues learn that giant mirror is actually a slow acting poison.