Raw Sewage is a burger made by Plankton to finally make a Krabby Patty without always failing. It only appears in the episode "Patty Caper." In that episode, Plankton tells SpongeBob that he is on a list in the alphabet, and that he is on the letter R, and to steal the secret formula.
The Raw Sewage burger looks similar to a Krabby Patty except it is darker in color. It also has dark-green sauce on it which resembles raw sewage. The ingredients look much more decayed and the patty contains a strange odor.
Role in episode
SpongeBob thinks that Plankton stole the secret ingredient for the Krabby Patty until he finds out that the burger is not a real Krabby Patty and just a failed duplicate attempt. After he and Patrick leave the Chum Bucket, Patrick is shown with bad breath coming out of his mouth, indicating that he ate the burger.
The Raw Sewage Patty looks similar to the Nasty Patty created by SpongeBob and Mr. Krabs in the episode of the same name. However, this patty was made on accident rather than purposely because Plankton was experimenting to find out the Krabby Patty formula.