'Rubber Duckie,' by Ernie from Sesame Street, won a Grammy nomination and reached #16 on the charts in 1970.
Rubber Duckie is Ernie’s signature song, which, as you might guess, is a tribute to his Rubber Duckie. It had the distinction of being both number 16 on Billboard’s “Hot 100 Singles” in 1970 and being nominated for a Grammy for Best Recording For Children (which was beaten by The Sesame Street Book & Record).
The first instance of the song appearing came in episode 78, when Ernie sang the song in his bathtub. The song has since been rerecorded a few times with different voice actors, but the same rubber duckie has always been used to match the sound of the original.
Other artists have also covered the song. Bob McGrath and Little Richard have both done recordings at one point. Most recently, the song was hummed in a 2010 episode. You can listen to the song here.