Nature Pants provides examples of:
- Ax-Crazy: Patrick, of all people, goes crazy when SpongeBob refuses to come home. He even threatens to put SpongeBob in a jar and keep him in there. Forever.
- Bad Bad Acting: Patrick in the scene below.
- Barbie Doll Anatomy: On SpongeBob, after he goes and lives with the jellyfish.
- Brick Joke: The poison sea-urchins.
- Hulk Speak: Patrick devolves to doing this during his breakdown.
- Ironic Echo Cut: "Even Squidward misses you." Cut to Squidward throwing himself a "Goodbye, SpongeBob" party.
- My God, What Have I Done?: When SpongeBob realizes the error of abandoning his normal ways.
- Nature Lover: What drives SpongeBob to live with the jellyfish.
- Noodle Incident: "That's the fifth time this week I had to scrape you off of something."
- Offscreen Crash: Patrick causes this when he throws aside the pile of SpongeBob's old phone books.
- Ominous Music Box Tune: When Patrick declares that he's going to make SpongeBob a trophy.
- Painting the Fourth Wall: Squidward references the episode's running time:Sandy: I give him a week.
Squidward: I give him eleven minutes.
- Please Put Some Clothes On: Squidward, when he gives SpongeBob his pants back at the end of the episode.
- Reading the Stage Directions Out Loud: Patrick, in this scene:
- Scenery Censor: When SpongeBob takes off his pants, he's standing behind a bush.
- Yandere: Patrick, full stop. A rare platonic example.
Airdate: September 11, 1999Squidward tricks Spongebob into believing it is opposite day, so he can try and move away from Spongebob.
Opposite Day provides examples of:
- Bad Impressionists: Patrick when imitating Squidward. He just goes "I'm Squidward, I'm Squidward" over and over in his normal voice.
- Big "NEVER!":Squidward: (clinging to the real estate agent's leg) Please sell my house!Real Estate Agent: (yanks her leg out of his grip) NEVER!
- Butt Monkey: Squidward, especially since he was trying really hard to sell his house in this episode.
- Getting Crap Past the Radar: In the German version, Squidward calls his neighbors "Barschgesichten" ("Perch faces"), a pun on "Arschgesichten" ("Ass faces").
- I Will Show You X: When Patrick and SpongeBob tell Squidward, "Happy Opposite Day, Squidward! We hate you!", Squidward gets ticked off before calmly saying, "Let me show you two how much I...HATE YOU!"
- I've Heard of That — What Is It?: The Trope Namer:Patrick: Opposite Day? Hey, I've heard of that!
Patrick: No, what is it?
- Not Their Birthday: The episode opens with SpongeBob and Patrick throwing Squidward a surprise birthday party. After they leave, Squidward yells at them that "It's not my birthday!"
- Opposite Day: Obviously.
- Screw This, I'm Outta Here!: Real Estate Agent, who's fed up with Squidward, SpongeBob, Patrick and Gary (pretending to be Squidward).
- Title Drop: Naturally.
- Voice Changeling: In the German dub, SpongeBob, Patrick and Gary can mimic Squidward's voice perfectly.