Onomatopoeia (comics) - Wikipedia, the free encyclopedia: "Onomatopoeia is a DC Comics supervillain who has faced Green Arrow and Batman. He first appeared in Green Arrow #12 (March 2002). He was created by writer Kevin Smith and artist Phil Hester. IGN's Daniel Crown called him 'one of the coolest new villains of the decade'.[1]"
... "His name is derived from the fact that he imitates noises around him, such as dripping taps, gunshots etc."