In every season of Dexter, Showtime's series about a Miami Metro Police Department forensics expert who stalks and kills other serial killers in his spare time, Dexter Morgan (played by Michael C. Hall) takes the lives of several criminals. He typically snuffs out run-of-the-mill killers in a single episode. More interesting ones may last three. The most diabolical evildoers of the bunch hack and slash (or burn or strangle or bludgeon) their way through the majority of a 12-episode season and become Dexter's nemesis before he turns them into a trophy blood slide. In the wake of season five's gripping finale, Complex looks back on the five sickest serial killers on Dexter (SPOILER ALERT!) to decide which of them is the most effed up.

By Justin Monroe (@40yardsplash)