The Worm from Appleworld lived in an apple under the sea.
For his brief appearance, in the episode "Rock-a-Bye Bivalve," he happily greeted SpongeBob and other fellow sea creatures just before being pulled from his apple home and eaten by Junior, a baby scallop. He only had two lines before being eaten.
His quote before being eaten: "Huh? Wait! We will bury you!" is a reference to a quote famously said by Soviet premier Nikita Khrushchev.