Nothing is known about the origin of Onomatopoeia. It is possible that he is from Delaware and had a brother who was killed by a masked criminal. In his secret identity he is apparently a well-adjusted and functional member of society, as he is married and has two children, none of whom are aware of his secret identity. He keeps a secret trophy case in which he displays the masks of the heroes he has killed. At some point he set his sights on the Arrow family.
Onomatopoeia was created by Kevin Smith and Phil Hester. He made his first appearance in Green Arrow #12.
Major Story Arcs
The Sound of Violence
Having killed two low-level heroes, Onomatopoeia focuses on a more famous target. He attacks Connor Hawke, the second Green Arrow, seriously injuring him. Hawke manages to escape, however, and Onomatopoeia tracks him to a hospital, intending to finish the job. He is prevented from doing so by Oliver Queen and Black Canary. They fight, and Onomatopoeia is struck with several arrows before falling from the hospital roof. Despite his injuries, he is able to escape
During the Infinite Crisis, Onomatopoeia appears to be affiliated with he Secret Society of Super Villains, as he is sent by that group to aid in the takeover of Metropolis. He battles Odd Man, and presumably later escapes.
Onomatopoeia aids the Joker in escaping from Arkham in an attempt to bait Batman. During the escape he shoots Deadshot in the head, but Deadshot survives. He encourages Joker to initiate a gang war with Maxie Zeus, luring Batman out in the process. He succeeds, but loses in hand-to-hand combat with the hero. He stabs the Joker in the heart, forcing Batman to choose whether to capture him or save the Joker. Batman remains with the Joker, allowing Onomatopoeia to escape.
The Widening Gyre
Onomatopoeia assumes the identity of Baphomet, a superhero in Gotham. He joins Batman in fighting Etrigan, and slowly wins Batman's trust in a series of encounters, ultimately earning Batman's approval for his vigilante activities. At one point, he fills in for Batman, fighting alongside Tim Drake, who is impressed by him. He eventually unveils what he claims to be his past and his secret identity. Eventually, Batman brings him to the Batcave and identifies himself as Bruce Wayne, introducing Onomatopoeia to Silver St Cloud. Onomatopoeia finally reveals his true identity by imitating the noise Batman makes when putting his utility belt on the table. Batman turns in time to see Onomatopoeia slitting Silver's throat.
Powers and Abilities
Onomatopoeia is an extremely skilled hand-to-hand combatant and athlete. He is a weapons expert and gifted marksman. He is very intelligent, and a skilled manipulator and liar. It is unknown whether Onomatopoeia has any superhuman powers or abilities. He is possibly superhumanly durable, given his ability to withstand unusually high levels of damage with little apparent effect, however this is unconfirmed.
When in costume, Onomatopoeia speaks entirely in onomatopoeias, imitating sounds around him. It is unclear whether his mimicry is exact or not, that is, whether for example he simply repeats the word "blam," or actually makes the noise of a gun being fired. As Baphomet, he has shown that this is not necessary to him, but rather a personal choice.
Weapons and Equipment
Onomatopoeia always wields two semiautomatic handguns, a sniper rifle, and a hunting knife. He is occasionally seen wielding other weapons, such as an axe or crossbows.
DC Nation Shorts
Onomatopoeia appears as the antagonist in the Green Arrow short "Onomatopoeiabot," as the creator of just under thirty powerful robots. They are defeated by Green Arrow and Black Canary. He attempts to slink away, but is spotted. He does not speak in his appearance.