Showtime Series

TVLine has compiled a ranking of the 15 most impactful villains from the original Dexter series on Showtime, highlighting antagonists who challenged the serial killer protagonist. The list tops with James Doakes as the greatest threat, followed closely by Arthur Mitchell and Brian Moser. Published on February 15, 2026, the article evaluates each character's danger to Dexter and their narrative influence across the show's seasons.