First appeared in JLX #1 in 1996 and was created by Gerard Jones, Mark Waid, and Howard Porter. J'onn J'onzz is an amalgamation of DC's Martian Manhunter and Marvel's Skrulls, Bishop, and Professor X. He was a Skrull from Mars who founded the Justice League X-Men (an amalgamation of DC's Justice League of America and Marvel's X-Men) and became known as Mister X.
Mister X (Amalgam) has been suggested to play 3 roles. Click below to see other actors suggested for each role, and vote for who you think would play the role best.