Hush

Hush, also known as Thomas Elliot, was a renowed surgeon and a childhood friend of Bruce Wayne's.

Biography
Thomas Elliot is a renowned surgeon and childhood friend of Bruce Wayne's. A meticulous planner, Elliot resents the fact that Bruce's father inadvertently thwarted his plot to kill his parents. While he went on to Harvard and became a successful surgeon, Elliot continued to hold an irrational grudge towards his childhood friend for having the "good fortune" he never had. He created for himself the identity of Hush, a mysterious, trench-coated criminal with his head wrapped in bandages, who often quotes Aristotle. He and the Riddler convinced and manipulated several other villains to help an elaborate plot against Batman, and after being defeated has continued taunt the Bat-family and menacing their allies. Recently, Elliot has surgically altered his face to look like Bruce Wayne's, planning to steal his identity.

Batman Beyond Unlimited

 * Legacy (mentioned, flashback)
 * Calling All Villains (flashback from episode of BTAC, "Hush")

Batman: The Adventure Continues

 * Fear Is Power (first apperance, as Thomas Elliot)
 * Hush (first apperance, as Hush)
 * Arkham City

Justice League Heroes

 * Hush Little Baby
 * Final Countdown, Part One
 * Final Countdown, Part Two (final apperance)

Movies

 * Batman Beyond Unlimited: Return of Hush