Never Smile at a Crocodile

From Muppet Wiki

Written by	Frank Churchill and Jack Lawrence
Music by
Lyrics by
Date	1952
Source	Peter Pan
Publisher	Walt Disney Music Co.

"Never Smile at a Crocodile" was sung by Mary Louise riding a crocodile through the swamp in episode 114 of The Muppet Show. Along the way various frogs get eaten by the crocodile.

The tune of the song comes from Disney's version of Peter Pan, with lyrics which were added later on subsequent record releases.