First appearance: New Teen Titans #2 (1980)
Created by: Marv Wolfman and George Perez
Most villainous act: Nearly killing the Teen Titans in “The Judas Contract.”

You don’t get any tougher than Deathstroke. This cold-blooded killer doesn’t just have advanced fighting abilities and a superhuman healing factor, he’s also one of the smartest tacticians in all of comics. This is a man who can out-think Batman and fight off half the Justice League all at once.

During the 1980s, fans weren’t just satisfied with seeing Deathstroke every few months as a villain; eventually, the demand for the character to have his own series forced DC to make him the star of his own book. Now Deathstroke is more of an anti-hero than a straight-up villain, but despite showing more compassion nowadays, the character hasn't lost the bloodlust we’ve come to love over the years.