A green and blue eel appeared several times on The Muppet Show.
In addition to background appearances on episodes 116, 117, 122, and 312, the eel performed 2 solo numbers. Both were the UK Spots on their respective episodes.
In episode 124, the eel, performed by Jim Henson, sang "When I'm Not Near the Fish I Love". In episode 417, he was performed by Jerry Nelson and sang "Three Little Fishies".