It is a giant Krabby Patty that is made with sesame seed buns, tomato, cheese, lettuce, and patty meat. It is able to talk.
Role in episode
After SpongeBob works 24 hours for several days at the Krusty Krab, he gets hypnotized by Plankton, who is pretending to be a psychiatrist. SpongeBob falls asleep and the Krabby Patty appears, telling him that it will always be with SpongeBob, and shows this by giving him a cookie pizza and some chocolate milk. It awakens him to find that he is cured by some sleep.