(written from a Production point of view)
In 1989, Greenquist co-starred with TNG actress Denise Crosby in the horror movie Pet Sematary. He also had a role in the 2001 biopic Ali, featuring TNG's LeVar Burton and Michael Dorn and Voyager guest star Bruce McGill.
He was a part of the cast of the 1996 mini-series Dead Man's Walk, starring Star Trek: Insurrection's F. Murray Abraham. He was also in the 2000 television movie Getting Away with Murder: The JonBenet Ramsey Mystery, as was DS9 guest actor Cliff DeYoung, Enterprise guest actor Holmes Osborne, and frequent TNG guest actress Gwynyth Walsh.
Greenquist also had roles in The Bedroom Window with DS9 guest star Wallace Shawn in 1987, the TV movie The Ransom of Red Chief with Trek movie actors Christopher Lloyd and Alan Ruck in 1998, and the films Crime and Punishment in Suburbia with Marshall Teague and Lost Souls with Star Trek: First Contact actress Alfre Woodard in 2000.
Greenquist guest starred in Heroes as a henchman working for George Takei's character, Kaito Nakamura.