Fulton MacKay as the Captain with Sprocket.
Fulton MacKay (1922-1987) was a Scottish born actor in British television and film. MacKay played The Captain, the British counterpart to Doc in the UK version of Fraggle Rock. MacKay died between the third and fourth seasons and was replaced by John Gordon Sinclair.
He also supplied the voice for the Gryphon in the Alice in Wonderland-inspired movie Dreamchild.
MacKay appeared on such British television comedies as Dad's Army, Porridge, and Wodehouse Playhouse. His other films include Local Hero.