8 Mysteries Even Batman Couldn't Solve

Created by Kevin Smith and Phil Hester for their 2002 run on Green Arrow, Onomatopoeia is one of the most fascinating modern villains in comics. He's also sadly a rogue who has been criminally underused since his first appearance.

Despite being introduced as an Emerald Archer villain, this unique bad guy is one who has also had the odd tussle with Batman. In particular, Smith and Walt Flanagan's The Widening Gyre tale in 2009 had Onomatopoeia completely outsmart the World's Greatest Detective.

To this day, the real identity of Onomatopoeia is a mystery that's yet to be solved. His face has been seen, his chillingly normal family life has been seen, we've heard about his past work in the mundane world of insurance, but not even Bruce Wayne has been able to crack the mystique that surrounds this serial killer.

For those not familiar with Onomatopoeia, he is a brutal and cold murderer who forever remains mute bar to mimic the sound of certain moments - such as mirroring the "Sssssslit" noise heard as he slit Silver St. Cloud's throat in The Widening Gyre.

Even worse, that murder only took place because Onomatopoeia had been invited into the Batcave by the Dark Knight. Having earned the trust of Batman as a new vigilante dubbed Baphomet, Onomatopoeia was shown the Batcave and even had Bruce unmask in front of him. All of which climaxed in the rogue revealing his real identity and slaughtering St. Cloud.