The line comes from Dexter, the Showtime crime series that ran from 2006 to 2013, where Sergeant James Doakes, played by Erik King, became known for suspecting Dexter Morgan. His blunt 'Surprise, motherfucker' delivery was clipped and reused in edits, remixes and YouTube Poop videos, turning a tense confrontation into a reusable Dexter meme. The short edit on this page keeps only the payoff, which is why creators still drop it into videos whenever a character, enemy or friend appears without warning.