- Frank the guard (debut)
- Prison guard
- Construction worker (orange)
- Purple construction worker
- Popeye fish
- Green prisoner
- Sheldon J. Plankton
- Karen Plankton
- Jellyfish (cameo)
- Octopus toy (cameo)
- Plankton's teddy bear (debut)
- Whale (cameo)
- SpongeBob SquarePants
- Eugene H. Krabs (mentioned)
- Patrick Star
- Squidward Tentacles
- Gary the Snail (mentioned)
- French Narrator
- Light purple officer
The episode begins with Frank the policeman showing a new cop around the prison. He then shows him the number one inmate, Plankton, who went to prison for stealing the Krabby Patty secret formula. However, due to the fact that his cell is not locked, he hides under Frank's mustache and escapes (the mustache becoming Plankton's hair).
He returns to the Chum Bucket, only for Karen to kick him out and give him his old guitar. Plankton then hears SpongeBob singing about a Krabby Patty while censoring out the ingredients with noises. Plankton asks him to sing it uncensored, however SpongeBob mistakes Plankton's appearance and wants him to join the band. Plankton rolls with it in hopes of stealing the formula.
SpongeBob then runs into Patrick and decides to let Patrick join due to his ability to play his stomach like a drum. Squidward begins criticizing them due to their lack of musical talent. However, when asked to join the band, he accepts with the thought of becoming famous.
SpongeBob, Patrick, and Plankton then start practicing while Squidward works out to look good. SpongeBob tells Patrick that he should dress with more pizzazz to look better for the band. Patrick shows SpongeBob his ponytail that he grew naturally. He then does tricks with his hair and grows more hair and sideburns.
Plankton returns with band shirts naming their band "Plankton and the Patty Stealers." Despite this, they are still oblivious to Plankton's true intentions. They quickly start working on their music afterwards.
Patrick keeps the seats warm (literally, since he actually puts firenunder the seats) while Plankton takes out his "recording equipment" and tries to record SpongeBob's Krabby Patty song, but he is unable to find it and his equipment overloads when Patrick wears the headphones. Plankton breaks down crying since his plan failed, but SpongeBob gives him hope, as Mr. Krabs lets them play at the Krusty Krab, after-hours. Meanwhile, now having achieved his "Perfect Dream Body," Squidward finally goes to practice.A week later, the band is all on their way to the Krusty Krab when a cop shows up in a police car. To prevent him from being recognized as an escaped convict, SpongeBob hides Plankton inside of his nose, disguised as a piece of dried nasal mucus. However, the police think nothing of it and drive off. The band then arrives at the Krusty Krab as Plankton unlocks the door.
Plankton immediately starts searching for the formula while the rest of his band rehearses. SpongeBob notices this and soon realizes that the band was another one of Plankton's dastardly schemes. Afterwards, the police come and arrest Plankton.
Now bald again, he is given a new cell inside of a safe. SpongeBob, Patrick, and Squidward visit him in prison, saying that their next performance would occur after his 22-year sentencing. The episode ends with them practicing and Plankton being tortured by it.
|( ‣ ) Associated production music|
|( • ) Original music|
|( ◦ ) SpongeBob music|
‣ Unknown Track 29 - opening
‣ Dramatic Impact 6 - Ivor Slaney ["He's gone!"]
‣ Blood in the Gutter - Laurie Johnson [Plankton escapes from the prison]
‣ Wooden Bear - Gil Flat, Tony Tape, Florian Voelxen ["Get out and stay out, you two-time loser!"]
‣ Toy Piano - Nicolas Carr, Barry Anthony [Flashback to Plankton's "band."]
‣ ? [SpongeBob sings about the Krabby Patty]
‣ Goofy Conversation - Nicolas Carr, Barry Anthony ["That was a delightful song you were singing."]
‣ Harp Ding - Nicolas Carr [Plankton gets an idea]
‣ Skipping to School - Sage Guyton, Jeremy Wakefield [Patrick joins the rock band]
‣ William Tell Overture - Patrick plays on his stomach
‣ Comic Walk - Sidney Torch ["Give me a break."]
‣ Vibe Sting - Nicolas Carr [SpongeBob gets an idea]
‣ Comic Walk - Sidney Torch [SpongeBob asks Squidward to join the band]
‣ Buzz Twist - Eric Spencer [Patrick's new hairdo]
‣ Surfmania - Eric Spencer [Patrick keeps Squidward's seat warm]
‣ Steel Sting (a) - Jeremy Wakefield ["I... love it!"]
‣ Unknown Track 26 - Nicolas Carr [Plankton growls]
‣ The Pollywog Strut - Nicolas Carr, Barry Anthony ["All we need are the lyrics."]
‣ Unknown Track 26 - Nicolas Carr [Plankton is seen with a machine]
‣ Tomfoolery - David Snell ["It's my... recording equipment."]
‣ Oh My Darling Clementine - "Time to feed him, time to feed him, now it's Gary's feeding time..."
‣ Row, Row, Row Your Boat - "Brush, brush, brush my teeth, gently keep them clean..."
‣ Lap Steel - Nicolas Carr [The machine explodes]
‣ O Makalapua (b) - Kapono Beamer [Plankton cries]
‣ Unknown Track 26 - Nicolas Carr [Band practicing]
‣ Unknown Track 37 - Nicolas Carr ["My perfect dream body!"]
‣ Grass Skirt Chase - Sage Guyton, Jeremy Wakefield [Squidward goes to practice]
‣ Hawaiian Link (b) - Richard Myhill [One week later]
‣ The Mob - Sam Spence [The police notice their band]
‣ Unknown Track 26 - Nicolas Carr ["Come on, come on, hurry up!"]
‣ Steel Licks (a) - Jeremy Wakefield [SpongeBob tries to unlock the door]
‣ Verve - Jack Shaindlin ["Yes! The Krabby Patty formula is mine!"]
‣ Dramatic Impact 1 - Ivor Slaney ["Now where does Krabs keep that formula?"]
‣ Bad to the Spongebone - Nicolas Carr, Barry Anthony, Roberto Vergara ["Whoo! Let's rock!"]
‣ Vibe Q Sting - Nicolas Carr ["Plankton?"]
‣ Drama Link (d) - Hubert Clifford [Plankton steals the formula]
‣ Hello Blues - Sage Guyton, Jeremy Wakefield [Plankton is back in jail]
‣ Unknown Track 26 - Nicolas Carr [Ending]
- This episode is available on the Spongicus, Season 6 Volume 1, Complete Sixth Season, and Next 100 Episodes DVDs.
- Some of the tough fish who were accepted into The Salty Spitoon in "No Weenies Allowed" appear in the beginning of this episode as prisoners.
- After SpongeBob sings his Krabby Patty formula song, he tells Plankton that Mr. Krabs told him that he had to censor the formula parts. One can infer that, as at one point, he sings an uncensored version of this song.
- Patrick plays the "William Tell Overture" on his stomach. The instrument being played is the timpani.
- Patrick has a natural talent to instantly grow hair in any style.
- The scene where SpongeBob says "Hey Plankton, can our first song be like this?" and makes a deep alarm noise then a high-pitched screech has become an internet fad, in which a dreadful noise will replace the alarm noise and the high-pitched screech. The fad is called "Hey Plankton".
- SpongeBob plays the bass guitar and it is a red version of the one that Mrs. Puff plays in "Band Geeks."
- The scene where the light purple officer see part of Plankton's green body hiding in SpongeBob's nose and think it is dried nasal mucus is foreshadowed earlier in the episode when Patrick says, "I found out where boogers come from."
- The secret formula is written in random letters.
- The Krabby Patty secret formula is revealed to have "humorous censorship" to keep viewers from discovering the secret formula themselves.
- Despite the episode title, Plankton, the Krusty Krab, and the secret formula being involved in the episode, Mr. Krabs does not appear; although, he is mentioned multiple times by SpongeBob.
- This was the first episode to premiere in 2008, but was still made in 2007 according to the credits.
- This was also the first season 6 episode to air, although it is the second episode in production order.
- This is the second time Plankton goes to jail. The first is in The SpongeBob SquarePants Movie.
- This is the second time a band is put together. The first was in "Band Geeks."
- This episode premiered two years after The Yellow Avenger was released on PSP and Nicktoons Unite! was released in the PAL region.
- In the German dub, this episode is called "Krabbenburger Blues," which translates to "Krabby Patty Blues."
- When Plankton first walks up to SpongeBob, he appears to be half of his size, but later he is much smaller.
- When Patrick plays the "William Tell Overture" on his stomach, several frames are missing in the loop.
- When Squidward tries to lift the weight and injures his arm, SpongeBob can hear him scream in pain over the phone. However, just before this, Squidward had hung up his phone, so SpongeBob should not have been able to hear Squidward's scream.
- SpongeBob's house's front door is way bigger than it usually is.
- When Plankton is inside of SpongeBob's nose, he has a lighter shade of green than he usually does.
- When Plankton unlocks the door to the Krusty Krab, the key is horizontal, but when the scene goes further away, the key is vertical.