DC's Deadshot and Marvel's Bullseye are two sharpshooters from troubled background who never miss their targets. The only real difference between them is that the former debuted 26 years before the Daredevil villain.
When DC pitted their skilled marksman against Batman in 1950, it worked so well that Marvel decided to pose a similar threat to its dark, street-level hero Daredevil in 1976.
The two villains share another thing in common: they've both been butchered on the big screen, Deadshot by Will Smith and Bullseye by Colin Farrell, but it's a Marvel property that can claim to have done that first.
Of course, there are differences between the characters besides their choice of costume. Chief among them is that Deadshot has dabbled in anti-heroism on occasion, while Bullseye is an out-and-out villain.