Tahmoh Penikett (; /tɑːmu ˈpɛnɪkɪt/; born May 20, 1975) is a Canadian actor. He is known for playing Karl "Helo" Agathon on SyFy's 2004 television series Battlestar Galactica. He has appeared in TV series Supernatural, Dollhouse, and the Showcase time travel show, Continuum.
Penikett was born in Whitehorse, Yukon. He is the son of former Yukon premier Tony Penikett, who moved to Victoria, British Columbia from England at age 12, and Lulla Sierra Johns, of the White River First Nation in the Yukon. He has two siblings, twin sisters Sarah and Stephanie. He graduated from the Victoria Motion Picture School and studied at the Lyric School of Acting in Vancouver.
In 2002, he had a brief appearance as one of the first Human-Form Replicators in the season 6 episode of Stargate SG-1, "Unnatural Selection". From 2004-2005, Penikett portrayed Ray Chase, who appeared in eleven episodes of the Canadian police drama, Cold Squad. He played a leading role as Noah Hamilton in the 2005 made-for-TV film Hush alongside actress Tori Spelling. He had a role in the video game Need for Speed: Carbon, as a street racer named Darius. He also appeared in four episodes of the television series Whistler as Elias Noth. Penikett also provided voice talent for antagonist Troy Hammerschmidt on the Adult Swim show Titan Maximum. In 2010, Penikett played the lead role of Matt Ellman on Syfy's miniseries Riverworld an adaption of the science fiction books written by Philip José Farmer of the same name. He starred in the first two episodes of Warner Brothers' Mortal Kombat: Legacy as Kurtis Stryker, which debuted in April on YouTube; he was replaced by Eric Jacobus for season 2.