The Rock Collector

watched an episode of a television series while he was imprisoned on Fortress Island, and occasionally whistled along with their "dialogue".

When the prison governor George Trenchard asked him what he was watching, the Master replied "It seems to be a rather interesting extraterrestrial lifeform." Trenchard responded "Just puppets, you know. For children." The Master appeared to express disappointment over this. (TV: The Sea Devils)

Behind the scenes
Although the episode and series went unnamed in TV: The Sea Devils, it was titled 'The Rock Collector ' in the real world, and was an episode in the original Clangers television series.