At the Krusty Krab, Squidward sends SpongeBob an order for a Krabby Patty, and it ended up in his nose. After making the patty, it begins to "move" and makes its way towards the front door. Mr. Krabs pulls Plankton out of the burger and sends him back to the Chum Bucket. Krabs explains that Plankton is his arch-competitor, and has been trying to steal the Krabby Patty's secret formula for years.
That night, after the Krusty Krab closes, Plankton tries to convince SpongeBob he and the fry cook are friends, and that as such SpongeBob should come to Plankton's birthday, as it is supposedly the following day. Plankton says that friends give each other things. Plankton asks SpongeBob what he thinks he'd like for a birthday present, and SpongeBob then guesses a booster seat. Plankton is very happy with that proposition, but refuses. Plankton tells SpongeBob that, for his birthday, he wants SpongeBob to give him a Krabby Patty. SpongeBob loudly and boldly refuses and runs back home, but Plankton promises that SpongeBob will "hand deliver it to (him) personally."
Later that night, Plankton enters SpongeBob's head through a pore and makes his way to SpongeBob's brain. He attaches a mind control device to the brain and bends SpongeBob to his will, forcing him to walk to the Krusty Krab, get a Krabby Patty, and bring it to the Chum Bucket's Laboratory. He brings it to an analyzer, which is designed to figure out the ingredients of whatever is dropped into it. As Plankton gloats over his victory and begins to force SpongeBob to drop the Krabby Patty, SpongeBob laments his failure to save it, lovingly describing the Krabby Patty's ingredients and succulence (ironically revealing the Secret Formula). A hungry Plankton leaps out of SpongeBob's head and onto the Krabby Patty, but bounces off of it and falls into the analyzer, thus trapping him inside his computer screen. SpongeBob walks home with the Krabby Patty in hand, ignoring Plankton's angry demands for him to bring it back, his last plea being "I'll settle for some fries!"
According to the captions, when Plankton speaks to Squidward through SpongeBob, he says Squidward's creations are "worth less than a protozoan's waist". This might be an error, as Plankton could have meant, "protozoan's waste." Since protozoans are extremely tiny creatures, and thus their waists would be small as well, it's possible that the captions were accurate.
Plankton has a record in which to dramatize his evil schemes. The record is Verve by Jack Shaindlin, and its B-side is The Alphabet Song sung by John Gosling.
Although it is not very likely, the scene where SpongeBob turned his head 180 degrees may have been a parody of, or reference to, the film "The Exorcist."
According to Karen, Plankton is 1% evil, 99% hot gas.
When SpongeBob is first making Krabby Patties, he throws one up in the air that disappears, probably because he had already put one in his head.
In Germany, the title doesn't change.
This is because the word "Plankton" in German is spelled out the same way as English.
Plankton was first introduced in this episode. Throughout the series, his voice is still deep, but has gotten higher-pitched and less villainous-sounding than what it was in this episode.
The scene when Plankton says "Come back here, you swine!" is sometimes cut because the word swine is offensive in some countries.
This is the first episode to have live action within the SpongeBob series.
A scene from Melon Felons appears on the big TV at the Chum Bucket, when it shows Plankton's "lab" (dog).
Plankton plays the nursery rhyme "This Little Piggy" on SpongeBob while trying to force him to drop the Krabby Patty.
When Plankton says "You weak-minded fool!," this is a reference to Star Wars: Return of the Jedi.
When SpongeBob walks into Squidward's room, it is on the first floor. However, in other episodes, it is on the second. It's possible Squidward moved upstairs.
When Mr. Krabs first appears on this episode, his first lines are "Avast ye patty pirate! This is no ghost. This is... Plankton!" When he says "This is no ghost," his mouth is visible; however, his lips do not move.
The captioning makes a spelling mistake for this episode. It spells "Krabby Patty" as "Crabby Patty."
When SpongeBob drops the golden spatula it is right next to him. When he walks away from Plankton, it is gone.
At night when SpongeBob is walking home, he moves his head to his left and right. The Krusty Krab then disappears.
The brain-control device says "Total Control," however, all Plankton controls is SpongeBob's movements and his words.
When SpongeBob first walks toward his pants, his tie is red. When SpongeBob's pants are pulled across his face, his tie is black. Right after his pants are back in there normal spot on the hanger, his tie is red again. This error also occurs in "Rock-a-Bye Bivalve."
SpongeBob is not wearing his uniform at the Krusty Krab.
Even though Plankton continues to try to find out the formula after this episode, SpongeBob revealed the entire formula in this episode with Plankton in his head. It is possible Mr. Krabs will might have fired him for SpongeBob doing that, or that Plankton thought SpongeBob was lying.
It is also possible that the secret is the exact ingredients proportions or the exact method to cook every ingredient.
When being forced into the Chum Bucket lab and screaming, SpongeBob's mouth doesn't move.