Nathan Fillion (b 1971) is a Canadian actor best known for his roles as Richard Castle on the ABC series Castle (with Stana Katic) and Captain Malcolm Reynolds in the television series Firefly and its feature film continuation, Serenity. His other credits include Steven Spielberg's Saving Private Ryan, voicing several versions of Green Lantern, Monsters University, Desperate Housewives, and Buffy the Vampire Slayer.
Fillion appeared in three ABC promos to promote The Muppets’ new series. In the first, his butt is a distraction to Miss Piggy. In another spot, he asks Kermit the Frog if their relationship is definitely over. In a follow-up, Fillion is seen leaving Piggy's trailer making the "walk of shame."