A depressed Plankton diffidently goes to the Krusty Krab one morning without a plan to steal the
formula, telling Karen that he will "wing it." When he goes inside, he slips on a wet floor and is ridiculed by Mr. Krabs. Two onlooking customers comment that there should be a wet floor sign and that they would sue Krabs if that happened to them. Plankton then pretends to be horribly injured, and threatens to sue unless Mr. Krabs gives him the formula, but Krabs obviously refuses.
Fearing that he will lose the case, Mr. Krabs hires a lawyer named Richard A. Bottomfeeder who tells him that he won't charge him anything unless they win and that they will counter-sue Plankton for everything he owns. Later, in Mr. Krabs' office, SpongeBob wants to read his testimony speech to Mr. Krabs. However, Mr. Krabs tells SpongeBob he could be a liability. As they prepare to leave for the court hearing, Bottomfeeder slips and falls, breaking his back. He gives SpongeBob his briefcase, saying, "The one thing you need to win this case is in this here case." SpongeBob takes Bottomfeeder's suit and arrives late to the hearing, dubbing himself "SpongeBob LawyerPants." When the first witness takes the stand, however, SpongeBob and Mr. Krabs realize that Bottomfeeder didn't give them the combination of the suitcase.
Plankton comes to court in a wheelchair and cast, and gives a convincing, earning the sympathy of the jury. Meanwhile, SpongeBob desperately attempts to open the case, but to no avail. Plankon uses the fact that Krabs does not own a "wet floor" sign as evidence against him, while SpongeBob only demonstrates Krabs' unhealthy greed in his attempts to defend him, accuses Plankton of being a fake, but the courtroom goes against Krabs. He then calls Squidward to the stand, but Squidward testifies against Mr. Krabs, saying that this is his only day off in three years.
Mr. Krabs tells SpongeBob to give up, but SpongeBob gives a short sermon telling him that they can't quit now. When he finishes, he hits the case lightly and it opens. They peer inside, only to find a Krabby Patty. Realizing that they can win the lawsuit with this, SpongeBob calls Plankton to the stand and seduces him with the Krabby Patty, eventually getting him to confess. Plankton then tries to steal the Krabby Patty, but is quickly stopped. The jury goes into deliberation and finds Mr. Krabs not guilty, but still proclaiming that he is cheap. SpongeBob then gives Mr. Krabs a homemade "wet-floor" sign, riddled with nails and shoddy paint. Mr. Krabs accepts the gift because it is free.
"Krabs vs. Plankton" was ranked #69 during the Best Day Ever event on November 9–10, 2006.
The title card music is the theme song from the TV show P.
When SpongeBob enters Mr. Krab's office, he is humming the end credits music.
When SpongeBob asks Plankton what he was doing in the Krusty Krab, he says, "To say hello to my once good friend Mr. Krabs, why?" This alludes to "Friend or Foe", which this episode predates.
Oddly, TurboNick calls this episode "Krabs vs. Patty".
Running Gag: People slipping on the wet floor. Mr. Krabs and SpongeBob struggling to open the case.
When SpongeBob said that Mr. Krabs being cheap was a "ludicrous statement", in many other episodes SpongeBob agrees that Mr. Krabs is cheap for example, in Krabby Land, SpongeBob said that all he saw was "Cheapy the Cheapskate" (Mr. Krabs), and in Pickles and Can You Spare a Dime?. SpongeBob calls Mr. Krabs a "crustaceous cheapskate" which kind of proves that SpongeBob thinks that Mr. Krabs is cheap.