The unnamed worm is an olive brown worm who made a cameo appearance when it got crushed by a Krabby Patty in the episode "Karate Choppers."
It is an olive green colored worm with white eyes and black pupils. He is fairly small in size and lives underground, in his grayish-tan colored sand hole. He is not like any other worms that were seen on the show because he is a brown worm and is quite small compared to the other worms.
Role in episode
The worm gets annoyed and got out of its hole to see what all the fuss was about and found out it was just a bunch of Krabby Patties and he eventually got hit by one of them.