Trevor Butterfield

Trevor Anthony Butterfield is a British actor and special effects technician.. He played several different roles in the Star Wars movies. He played an Imperial Officer and a Stormtrooper in The Empire Strikes Back (1980) and Bossk (filling in for Alan Harris), Lieutenant Blount, a Stormtrooper, Calamari Warrior and Giran in Return of the Jedi (1983).

He was credited as a (senior) special effects technician for many major film productions including Aliens (1986), Indiana Jones and the Last Crusade (1989), Hudson Hawk (1991), Mission: Impossible (1996), Daylight (1996), Mortal Kombat: Annihilation (1997), Legionnaire (1998), Prometheus (2012) and six of the Harry Potter films (2003-11).

I met Trevor at the Something Bl**dy Awesome convention in Edinburgh in April 2014.

Link:
IMDb

Trevor Butterfield as Lt. Blount in Return of the Jedi