Smellies are creatures who only appear in the episode "The Thing."
They are covered with light gray fur and have a leaf-like object on their heads.
SpongeBob and Patrick mistake Squidward for one of these creatures after he got stuck in cement and took on a similar appearance. After the SWAT Team captures him and takes him to the zoo, SpongeBob and Patrick rescue Squidward and escape into a jungle-like landscape. Inside they find Kelpy G playing his clarinet, along with several Smellies that are listening to the music. Squidward and the Smellies enjoy the music, but after Squidward's cement breaks off, the normal Smellies look at him strangely.