It can't be... can it?

On this Monday's episode of Castle Season 5, hilariously titled "The Fast and the Furriest," Rick and Kate come across enormous footprints at the scene of a murder, leading at least one of them to wonder:

Is Bigfoot behind the crime?!?

Watch Espo set the scene in this clip:

Elsewhere, Once Upon a Time favorite Raphael Sbarge will guest star as a man who piques Castle's interest even more in this elusive creature. Watch their exchange below:

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.