- 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 opens 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, because 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 (calling him a two-time loser, implying that he may have cheated on her with a female convict) 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 afterward.
Patrick keeps the seats warm (literally, since he puts a fire under 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 and becomes furious. Plankton tries to prove his innocence. Afterward, 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 closes with them practicing and Plankton being tortured by it as he shrieks agonizingly.
|( ‣ ) Associated production music|
|( • ) Original music|
|( ◦ ) SpongeBob music|
• Clownfish Capers - Sage Guyton, Jeremy Wakefield [Title card]
• Suspended Suspense - Nicolas Carr [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."]
• Great Idea Patrick - 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."]
• What's This - 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 Licks 10 - Jeremy Wakefield ["I... love it!"]
• Wig Struck - 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]
• Birth of the Krabby Patty - 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 8 - 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, Slumber Party, SpongeBob's Legendary Adventures, The Ultimate SpongeBob Box Set, SpongeBob SquarePants Vol. 9, Kids Double Pack: Volume 6, Complete Sixth Season, The SpongeBob SquarePants Collection, 3 DVD Value Pack Volume 2, Welcome Aboard, Sheldon Plankton: Mean and Green, Time Travel, The SpongeBob SquarePants 8 Season DVD Collection, Next 100 Episodes, and The Best 200 Episodes Ever DVDs.
- "Krabby Road" was ranked #37 during the SpongeBob's Top 100 event in the UK and Ireland from June 4-8, 2012.
- Some of the tough fish who were accepted into The Salty Spitoon in "No Weenies Allowed" appear at 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."
- Foreshadowing: The scene where the light purple officer sees 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.
- Irony: After finding the secret formula, Plankton should've exited through the back door in the kitchen to avoid detection from SpongeBob.
- This is the first episode to premiere during the Gimme 5 event.
- This is also the first episode to premiere in "Season 6".
- This is the second time Plankton goes to jail. The first is in The SpongeBob SquarePants Movie.
- In the Bahasa Indonesia dub, the scene where SpongeBob recruiting Patrick and Squidward was simply cut due to time constraints.
- 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.
- The front door on SpongeBob's house is way bigger than it usually is. This could be justifiable since Squidward in a perfect shape can't fit when his door is normal size but will in a bigger door. This error also occurs in "Waiting."
- 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.