(written from a Production point of view)
For the Star Trek: Voyager episode "Warlord", Greenquist filmed his scenes on Thursday 29 August 1996, Friday 30 August 1996, and Monday 9 September 1996 on Paramount Stage 8, 9, and 16. His costume was later sold off on the It's A Wrap! sale and auction on eBay. 
In 1989, Greenquist co-starred with Star Trek: The Next Generation actress Denise Crosby in the horror movie Pet Sematary. He also had a role in the 2001 biopic Ali, featuring LeVar Burton and Michael Dorn and Bruce McGill.
He appeared with John Glover in two television movies, Assault at West Point: The Court-Martial of Johnson Whitaker in 1994 and Dead by Midnight in 1997.
Greenquist was part of the cast of the 1996 mini-series Dead Man's Walk, starring F. Murray Abraham. He was also in the 2000 television movie Getting Away with Murder: The JonBenet Ramsey Mystery, as were Cliff DeYoung, Holmes Osborne, and Gwynyth Walsh.
Greenquist also had roles in The Bedroom Window with Wallace Shawn in 1987, the television movie The Ransom of Red Chief with Christopher Lloyd and Alan Ruck in 1998, and the films Crime and Punishment in Suburbia with Marshall Teague and Lost Souls with Alfre Woodard in 2000.
Greenquist guest starred in Heroes as a henchman working for George Takei's character, Kaito Nakamura.