Tahmoh Penikett ([ˈtaʔmo] ; born May 20, 1975) is a Canadian actor and martial artist. He is best known for playing Karl "Helo" Agathon on SyFy's television series Battlestar Galactica. He has starred in TV series Supernatural, Joss Whedon's Dollhouse, and the Showtime time travel show, Continuum.