Spoiler alert!
Warning! This page contains spoilers of an episode that has recently aired in Scandinavia and has recently been released digitally in France, Israel, South Africa, and the United States. Do not continue reading if you wish not to be spoiled.

"Knock Knock, Who's There?" is a SpongeBob SquarePants episode from season twelve. In this episode, SpongeBob watches Mr. Krabs's house while he's away, so he takes extreme measures to make sure no one breaks in.



Mocking SpongeBob
This section contains speculative information. This information has not been confirmed. Please keep this in mind.
The episode beings with Mr. Krabs informing SpongeBob at his house that he is out for the night to the Bikini Bottom Convention Hall and tells him to guard the house while he is gone. While he's gone, SpongeBob checks to see if everything is right in the house. He then orders pizza, but forces the mailman to slide it through the mail slot. Meanwhile at the convention, Mr. Krabs is unqualified to enter because he fails to present any money to the admission. Another fish who brought just a coin is admitted into the convention and is rewarded a giant stash of money, making Mr. Krabs extremely jealous.

At the same time, SpongeBob is watching a scary movie on TV. Mr. Krabs comes home and knocks on the door as he is locked out, frightening SpongeBob with a double-scare. Assuming he's a burglar, SpongeBob refuses to let him in. Mr. Krabs resorts to squeezing through the mail slot, but he's too big. He then climbs up to his top window, but is struck by lightning in the process. He then tries to get in through his bottom window, but is sprayed with perfume as part of one of the booby traps. He attempts to get inside through venturing the sewers and climbs his way up out the toilet, but SpongeBob uses a plunger to flush him back down. Afterwards, he slides through his pet door on the backside of his house, but is crushed by a giant metallic block of cheese.

Mr. Krabs finally resorts to destroying his living room wall with a wrecking ball. As he swings on the ball through the destroyed wall, he slams onto the second wall and gets two black eyes. Just as Mr. Krabs is about to confront SpongeBob and Patrick, he is imprisoned in a giant laundry bin and a block of concrete drops on him, but instantly recovers when SpongeBob and Patrick remove the booby trap. The two then apologizes to him for refusing to let him in and believing him to be a burglar. However, the conflict restarts when they hear another voice from outside attempting to invade the house and believe to be a burglar, who turns out to just be Pearl trying to get back inside.

Running gags

  • SpongeBob spraying the bottle of perfume.
  • Mr. Krabs trying to sneak into his own house only to fail and get booby-trapped each time until the end.


The episode was confirmed by Vincent Waller on June 29, 2019.[2]


 ) Associated production music
 ) Original music
 ) SpongeBob music
  Ahoy Landlubbers - Michael Bolger, Nicolas Carr [Title card]

  Mister Wobble - Jack Jordan [Opening at Mr. Krabs' house]
  Hot Steel and Slide Licks 39 - Jeremy Wakefield ["I've got me private things in there."]
  Laughter Trombone - [ProjectSAM Symphobia Colours: Animator] [Krabs laughs]
  Mister Wobble - Jack Jordan [SpongeBob lifts his arms without his hands]
  Laughter Muted Trumpet - [ProjectSAM Symphobia Colours: Animator] [SpongeBob's arms deflate]
  What's This - Nicolas Carr [SpongeBob's hands are back in his arms]
  Mister Wobble - Jack Jordan [Krabs leaves his house]
  Hot Steel and Slide Licks 23 - Jeremy Wakefield [SpongeBob sighs]
  Melodramatic Moments - Michael Bolger, Nicolas Carr [Krabs gives SpongeBob his last advice]
  Mister Wobble - Jack Jordan [SpongeBob hits Krabs' face with the door of his house]
  Bubble Popping Boys - Nicolas Carr, Barry Anthony [SpongeBob checks Krabs' house]
  Victory Chords - [ProjectSAM Symphobia Colours: Animator] [SpongeBob notices a door in Krabs' house]
  Bubble Popping Boys - Nicolas Carr, Barry Anthony [?]
  Flashback - Nicolas Carr [SpongeBob remembering Krabs' advice]
  Mister Wobble - Jack Jordan [SpongeBob remembering Krabs' advice]
  Hot Steel and Slide Licks 2 - Jeremy Wakefield [SpongeBob's feet are barefoot]
  Tricks and Traps - James McConnel [SpongeBob checks Krabs' bedroom]
  Sylvia Celesta - Leo Delibes, Frederic Sans [SpongeBob discovers a music box with a figurine of Mrs. Puff]
  Full of Beans - Robert Schreier [Closeup of Krabs' Midnight Pincer perfume]
  Sylvia Celesta - Leo Delibes, Frederic Sans [SpongeBob sprays himself with perfume]
  Tricks and Traps - James McConnel [SpongeBob pulls strings destroying the pictures]
  Drama Link (f) - Hubert Clifford [SpongeBob screams]
  Kalua Jubalee - Sage Guyton, Jeremy Wakefield [Pizza is delivered]
  Handy Pandy - Cedric Palmer [Krabs arrives at the Fast Food Founding Fathers convention room]
  Film Fanfare (a) - Dick Walter [Fish earns money]
  Beautiful People (a) - David Walter, Dick Walter [First TV channel]
  Acrobats and Clowns A - Alfi Kabiljo [Second TV channel]
  Unknown Track 69 - Third TV channel
  Teenage Kicks - Bert Weedon [Fourth TV channel]
  New Threat - Roger Roger [SpongeBob watching a horror movie]
  Punctuations - Ralph Dollimore [SpongeBob hears someone knocking on the door]
  Comedy Punctuations and Bridges 3 - Fredric Bayco [Krabs knocking the door/He tastes the pizza remains/?]
  Stool Pigeon - Kenny Graham [SpongeBob doesn't let Krabs enter]
  Alone and Lost - Norman Dane [SpongeBob calls Patrick for help]
  Capering Clowns - Max Saunders [Krabs sees Patrick arriving at his house]
  Nude Sting - Nicolas Carr [Closeup of Patrick]
  Crime and Danger Sign #2 - Hans Conzelmann, Delle Haensch [SpongeBob and Patrick hear noises]
  Tricks and Traps - James McConnel [Lightning falls on Krabs]
  Crime and Danger Sign #2 - Hans Conzelmann, Delle Haensch [SpongeBob decides to put traps]
  Comical Clowns - Ronald Hanmer [SpongeBob and Patrick put more traps for Krabs]
  Crime and Danger Sign #2 - Hans Conzelmann, Delle Haensch [Krabs breaks a window to get inside]
  Full of Beans - Robert Schreier [?]
  Crime and Danger Sign #2 - Hans Conzelmann, Delle Haensch [Krabs falls on the floor]
  In Disguise Wah Trumpet - [ProjectSAM Symphobia Colours: Animator] [Krabs is muddy]
  Bad Slide - [ProjectSAM Symphobia Colours: Animator] [Patrick hits Krabs with a pillow]
  Lap Steel - Nicolas Carr [Transition to next scene]
  Fraidy Cat - Fredric Bayco [Krabs tries to enter his house through the bathroom]
  Hot Steel and Slide Licks 1 - Jeremy Wakefield [Transition to next scene]
  Fraidy Cat - Fredric Bayco [Krabs attempts to use the back door]
  Dramatic Cue (d) - Ronald Hanmer [Giant cheese falls cutting Krabs' eyelashes]
  Vibe Q Sting - Nicolas Carr ["Hmm... cheddar."]
  ? [Rimshot]
  Eight Dramatic Bridges - Ronald Hanmer [Krabs is very angry]
  Another Goofy Cue - Nicolas Carr, Barry Anthony [SpongeBob and Patrick in the living room]
  First in Command - Gregor Narholz [SpongeBob and Patrick watching TV]
  Hot Steel and Slide Licks 23 - Jeremy Wakefield ["Wow! 3D!"]
  Eight Dramatic Bridges - Ronald Hanmer [Krabs approaches SpongeBob and Patrick angrlily]
  Hot Steel and Slide Licks 8 - Jeremy Wakefield [Krabs crying]
  Ahoy Landlubbers - Michael Bolger, Nicolas Carr [?]
  Punctuations - Ralph Dollimore [Pearl knocks at Krabs' house]
  Sylvia Celesta - Leo Delibes, Frederic Sans [Ending]



  • When SpongeBob pulls on a loose string on one of Mr. Krabs' knots, the entirety of his knot collection comes undone, which is a callback to "The String."
  • The live-action mouth SpongeBob makes while calling Patrick returns for the first time since "Mermaid Man and Barnacle Boy VI: The Motion Picture."
  • The portrait of the snail that looks like Gary which is hung in SpongeBob's living room appears in Mr. Krabs' house.
  • Mr. Krabs is revealed to own a figurine of Mrs. Puff which is kept in a small blue treasure chest, which dances on a cake.
  • This is the fourth episode where SpongeBob imitates Mr. Krabs. The first is "Gone," the second is "Mimic Madness," and third is "Boss for a Day."
  • This episode premiered digitally on Dish on Demand on September 27, 2020.
    • This is the second episode to be released on a digital Dish platform, the first was "My Two Krabses."
  • Mr. Krabs is revealed to have a sliding pet door at the back of his house.
  • SpongeBob flips through the channels to see live-action footage of a yellow fish, a coconut tumbling down the hill, a wrestling match between two humans, and a black-and-white horror film involving a fish hook.
  • The Conch Shell makes an appearance in the episode.
  • The F.F.F.F. customer getting cash from the F.F.F.F. entry fish after given a penny is what happens at the Krusty Krab in the episode "Clams."
  • "Hot Steel and Slide Licks 23" plays for the first time since after "High Sea Diving."

Cultural references

  • The title of this episode references the first two exchanges between the teller and recipient of a knock-knock joke.


  • The title card misspells the episode by improperly placing the comma after the first "Knock" instead of the second one.
  • In one scene, SpongeBob's eyelashes disappear.
  • After SpongeBob throws the remote, his bucket of popcorn, and his blanket in a frightened response, they are nowhere to be seen in the living room afterward.

English title card in Hebrew dub for a frame

  • In the Hebrew dub, the English title card was accidentally shown for a frame.


  1. ^ Google archive of the episode page is from this date.
  2. ^
Community content is available under CC-BY-SA unless otherwise noted.