Scott MacDonald Scott MacDonald ( born ) is an actor who has appeared in all of the first four " Star Trek " television spin - offs . His most frequent " Star Trek " role was that of the Xindi - Reptilian , Commander Dolim during the third season of . After his first appearance as Tosk in DS9 ' s , MacDonald was promised a less makeup - intensive role in any future " Trek " appearances . However , three more characters he played required extensive makeup : that of a Romulan , a Jem ' Hadar and a Xindi - Reptilian . However , he did get the opportunity to play a Human – Ensign Rollins – in , the pilot episode of . During this episode , his character was placed in command of USS " Voyager " while the senior officers were away – a rarity for a non - regular character in " Star Trek " . Career . Television . MacDonald ' s 1993 appearances as Tosk and N ' Vek on " Deep Space Nine " and " " , respectively , were his first television roles . He has appeared on several other science fiction / fantasy shows since then , including " Kindred : The Embraced " ( with Jeff Kober and Brian Thompson ) , " Space : Above and Beyond " ( with Lanei Chapman , Marnie McPhail , and James Parks ) , " Charmed " ( with Michael Bailey Smith ) , " The X - Files " ( with Wade Williams ) , and Sci - Fi Channel ' s " " . Some of MacDonald ' s early non - " Trek " TV credits included appearances on " Frasier " ( starring Kelsey Grammer ) , " NYPD Blue " ( starring Gordon Clapp and Sharon Lawrence ) , " Family Law " ( with Christopher McDonald , Tracy Middendorf , and Salli Elise Richardson ) , and " The Practice " ( with Bill Smitrovich ) . He later guest - starred in episodes of " CSI " ( with Wallace Langham ) , " Crossing Jordan " ( with Cliff DeYoung , Miguel Ferrer , and Clint Howard ) , " NCIS " ( directed by Terrence O ' Hara ) , " The District " ( with Roger Aaron Brown , Frank Novak , and John Savage ) , " JAG " ( with David Andrews , Scott Lawrence , Richard Lineback , and Zoe McLellan ) , and " Dexter " ( with Brad William Henke ) . MacDonald appeared in a 2003 episode of " The Lyon ' s Den " called " Trick or Treat " . Among the cast of this episode were former " Voyager " cast members Roxann Dawson and Robert Picardo , fellow " Deep Space Nine " guest star Steven Weber , and " Enterprise " co - star Rick Worthy . Three years later , MacDonald was seen on " Boston Legal " , starring William Shatner and Rene Auberjonois . He was most recently seen in a 2009 episode of " Without a Trace " , on which Enrique Murciano was a regular . Recurring roles . MacDonald was a recurring actor on the HBO series " Carnivàle " , on which he played the role of Burley . Among those he worked with on this series were fellow " Trek " alumni Adrienne Barbeau , Clancy Brown , K Callan , John Fleck , Ellen Geer , Leonard Kelly - Young , Thomas Kopache , John Carroll Lynch , Matt McCoy , Diane Salinger , John Savage , and Time Winters . After " Carnivàle " , MacDonald played the recurring role of Captain Manning on the science fiction series " Threshold " . This series starred Brent Spiner and was produced by André Bormanis and David Livingston and executive produced by Brannon Braga ; Mike Sussman was the show ' s supervising producer . MacDonald also worked with Jacqueline Kim on this series and appeared in at least one episode written by Sussman . Films . MacDonald has appeared in several films , beginning with 1993 ' s " Fire in the Sky " ( with Noble Willingham ) . In 1996 , he played the title role in the horror movie " Jack Frost " and returned to the role for a direct - to - video sequel subtitled " Revenge of the Mutant Killer Snowman " in 2000 . ( The latter starred Ian Abercrombie ) . In 2005 , MacDonald gave a memorable performance as Drill Instructor Fitch in the acclaimed war film " Jarhead " . His other film credits include " Bad City Blues " ( 1999 , with Simon Billig , Michael McGrady and Jim Metzler ) , " Seven Girlfriends " ( 1999 , with Olivia d ' Abo , Michael Buchman Silver , Stephanie Erb , Steve Vinovich , Georgann Johnson , Lisa Lord and Ivar Brogger ) , and " Straight Into Darkness " ( 2005 , with Daniel Roebuck and David Warner ) . He can also be seen in the made - for - TV movies " The Rat Pack " ( with David Andrews , Brad Blaisdell , and Dey Young ) , " Babylon 5 : A Call to Arms " ( 1999 , with Marjean Holden , Tracy Scoggins , and Tony Todd ) and the Gulf War film " Jarhead " ( 2005 , with Dendrie Taylor ) . Stage . MacDonald portrayed Damis in a 1988 production of " Tartuffe " for the Seattle Repertory Theatre . His other credits with the company include productions of " Richard III " ( portraying Richmond ) and " The Understanding " ( as Raff ) . He also did several productions with Seattle ' s Intiman Theatre , including the lead roles in " A Streetcar Named Desire " and " Hamlet " . MacDonald played the dual role of Patrick and Scotty in Robert Schenkkan ' s Pulitzer Prize - winning series of one - act plays entitled " The Kentucky Cycle " . The plays began in Seattle and ultimately transferred to Broadway , where it ran for 15 previews and 33 performances from 14 November 1993 through 12 December that same year . Among the actors MacDonald performed with on " The Kentucky Cycle " since its beginning were Gregory Itzin and Randy Oglesby .