When the crew of the USS Enterprise was trying to convince the cosmic cloud not to consume Earth, images from the ship's library computer were shown to the non-corporeal lifeform, and one of those images showed the silhouettes of children running in the country with a collie. (TAS: "One of Our Planets Is Missing") The collie was none less than Lassie, star of Lassie's Rescue Rangers, as the images were re-used footage from that show.