The Gills Brothers
Fish vocal quartet appearing in several episodes of The Muppet Show. They debuted as a backing band for Kermit, Piggy, and Robin the Frog's cover of the Beatles' "Octopus's Garden" in the 12 Oct. 12 (US)/8 Dec. (UK) 1978 episode. They later performed solo and with The Fish Singer.
They are a parody of the real vocal quartet (and later trio) the Mills Brothers.