Known for Acting

Mark Andreas Sheppard (born 30 May 1964) is a British actor and musician. He is often credited as Mark A. Sheppard. Sheppard is known for playing the demon/King of Hell Crowley on Supernatural and for his recurring roles as lawyer Romo Lampkin on the Battlestar Galactica reboot, Interpol investigator James Sterling on Leverage, and small-time crime lord Badger on Joss Whedon's Firefly. Description above from the Wikipedia article Mark Sheppard, licensed under CC-BY-SA, full list of contributors on Wikipedia.
1993
as Paddy Armstrong
2004
as Leitch
2007
as Malcolm
2010
as Young Captain Nemo
2010
as Dr. Charles LeBlanc
2001
as Ian Fields
1996
as Nigel Bowles
1999
as Fang
2001
as Yuri
2004
as Mitchell Parks
2003
as Chomsky
2013
as Ackley
1999
as Christopher 'C.J.' Yates
2013
2001
2004
as Peter
2000
as M. J.
2013
as Self
—
as The Ringmaster
—
as California