He is a dark green pet worm with light yellow-green and black eyes. He has a black leash.
He first appears in the episode "Sandy's Rocket," as one of the characters who got trapped in a moon rock sack by SpongeBob and Patrick. His name was revealed in his final appearance, "As Seen on TV," where it is shown that he enjoys sniffing things and taking walks. He, like all worms, is an underwater equivalent of a dog, as snails are those to cats. Mr. Doodles is not shown to be vicious like Guard Worms, he just likes to bark and be walked by his owner, Eugene H. Krabs. He is a good companion to have, as shown in "As Seen on TV" like all worms are to their fish owners.
This character has not appeared outside of the pre-movie era.