Plankton starts dating Mr. Krabs' mother.
"Enemy In-Law" contains examples of:
- Guess Who I'm Marrying?: Mrs. Krabs dates Plankton despite Mr. Krabs thinking it's a plot to steal the formula. But when Plankton asks Mrs. Krabs to marry him, she refuses, because she's already dating Plankton's giant robot.
- "How Did You Know?" "I Didn't.": After finding out that his mother's new boyfriend is Plankton, Mr. Krabs storms into the Chum Bucket and demands that he stop trying to get the formula out of her, only for Plankton to express surprise that his mother knows the formula.
- Humongous Mecha: Plankton has one that he uses to kidnap people and bring them to the Chum Bucket and uses it to try and whoo Mrs. Krabs. She later ends up dating it.
- Hypocritical Humor: Mr. Krabs notes that he can't act like a child by cowering over his mother marrying Plankton and has to deal with it like a man. He then leaps onto his mom's lap and childishly begs her not to accept Plankton's marriage proposal, referring to him as a "bad bad man".
- Parent with New Paramour: Upon hearing his mother has a boyfriend, Mr. Krabs is supportive since it means he will no longer have to buy his mother anything she wants until finding out that it's Plankton, believing that it's all a trick to get her to tell him the formula.
- Rocky Roll Call:Mr. Krabs: Plankton!
Mr. Krabs' Mom: Eugene!
Mr. Krabs: Mommy?!
Mr. Krabs: SpongeBob!
- Stalker with a Crush: Plankton calls Mrs. Krabs to ask her on a date after giving her a new hat she wanted. She jokingly asks him if he had been spying on her only to show that Plankton does indeed have cameras around her house.
- Your Cheating Heart: Plankton falls in love with and date Mrs. Krabs despite already being married to Karen.
Mermaid Man and Barnacle Boy VI: The Motion Picture
SpongeBob and Patrick are shocked to discover the new Mermaid Man and Barnacle Boy movie are being played by "actors", and decide to make their own movie starring the real Mermaid Man and Barnacle Boy.
"Mermaid Man and Barnacle Boy VI: The Motion Picture" contains examples of:
- Amateur Film-Making Plot: The episode involves SpongeBob attempting to make a film for Mermaid Man and Barnacle Boy to compete with the new modern movie coming out. When the movie is made, it turns out to be absolutely terrible. Mermaid Man and Barnacle Boy, however, are just happy to know they still have some "action" within them.
- Body Horror: The way Squidward does Mermaid Man and Barnacle Boy's "make-up".
- Camera Obscurer: It turns out Patrick put the lens cap on the camera before filming so he doesn't lose it, meaning none of the footage was recorded.
- Everybody Laughs Ending
- Funny Background Event: After the movie finishes, while SpongeBob, Patrick, Mermaid Man, and Barnacle Boy express how proud they are of the movie, everyone else in the audience appears disappointed and unamused.
- Metaphorgotten: After SpongeBob starts to despair about the movie not getting made, Mermaid Man tries to cheer him up with this:Mermaid Man: Hey, little hero, this reminds me of the Episode 912. We were surrounded. The Kelp-Thing was to our right and their broccoli was on the side. But if there was one thing I remember, it was how to forget. The rain in Spain stays mainly on the...space! The final countdown. Stick to the...stick to the...Lou, my darling! Lou! (falls dramatically into SpongeBob's arms) Now get out there and finish this movie, kid.
- Obvious Stunt Double: It's obvious Sandy's doubling for Mermaid Man in the movie they make.
- Running Gag: Sandy blowing something up when somebody says "boom".
- "Shaggy Dog" Story: After the set is destroyed, SpongeBob is still relieved that they got the footage, only to discover that Patrick left the lens cap on the camera.
- Synchro-Vox: Used when SpongeBob is discussing "actors" being used in the Mermaid Man and Barnacle Boy movie.