- French Narrator
- SpongeBob SquarePants
- Squidward Tentacles
- Patrick Star (in a picture)
- Gary the Snail
- Live-action dolphins (debut)
- Singing scallops (debut)
A jellyfish insists on following SpongeBob home after a day out at Jellyfish Fields, so SpongeBob decides on keeping it as a pet at his home. Squidward warns SpongeBob that jellyfish are wild animals and that they should not be domesticated, but SpongeBob completely ignores him. At home, SpongeBob dances with the jellyfish to loud techno rave music, which annoys Squidward to no end. After 12 hours of this form of nonstop partying, SpongeBob finally decides that it is time to go to bed, but this Jellyfish does not want to stop. SpongeBob eventually forces it to go to bed by tying a leash around it and ties it to his bed. Gary tries to tell SpongeBob he shouldn’t be keeping a wild animal, but SpongeBob doesn’t listen. During the night, while SpongeBob sleeps, the jellyfish escapes and brings lots of his friends into his house.
The next morning, SpongeBob wakes up to find his living room filled with hundreds of dancing jellyfish. He attempts to make them leave, but to no avail. Squidward, annoyed that the music has been going on for 18 hours and has not been able to get any sleep all night, angrily calls SpongeBob on his conch phone to tell him that he's had enough of the loud music. A jellyfish picks it up and sprays him with jelly over the phone. Irritated, Squidward decides that "two can play at this," and starts loudly playing his clarinet, angering the jellyfish with his terrible playing, who start destroying SpongeBob's house. SpongeBob asks Squidward to play his clarinet a little "better," as an insulted Squidward sarcastically responds this request. However, Squidward intentionally starts playing even worse and much louder with megaphones and a microphone. This prompts the jellyfish to angrily go to his house, as he cowardly tries to promise to stop playing, but they sting him before returning to SpongeBob's house. A sting-covered Squidward says to SpongeBob "Everybody's a critic. You won't be hearing from me anymore," and gives him his clarinet before leaving. The jellyfish hastily take it from SpongeBob, break it in half, burn it, and dance around it.
This further angers SpongeBob, who attempts to remove the stereo system, destroying it in the process, and the infuriated jellyfish begin stinging and chasing him. SpongeBob and Gary go up to the roof of the house, but the swarm follows them outside and surrounds them. SpongeBob tells Gary that he was right. Then Gary drives them away by clicking his eyes together, producing a sound that calms the Jellyfish. SpongeBob tells Gary to keep doing this, and puts him on his head. SpongeBob walks downstairs and out the front door, with the Jellyfish following him. As he leads them back to Jellyfish Fields, more sounds join Gary's clicking, eventually becoming a full-fledged song. Taking advantage of them being distracted, SpongeBob quickly flees the area with Gary.
In the last scene, SpongeBob shakes with Gary as the French narrator declares “Today SpongeBob has learned one of the sea’s harshest lessons wild animals can throw very wild parties” then the severely stung Squidward is shown getting into his bathtub to recover from his stings and the French narrator declares "Ooh, I felt that" as the episode ends.
|( ‣ ) Associated production music|
|( • ) Original music|
|( ◦ ) SpongeBob music|
‣ Lonely on the Beach - The Hawaiian Serenaders, Jan Rap [opening]
‣ O.K. Mr. Hillbilly (Instrumental) - Roy Henley [SpongeBob "milking" a jellyfish]
‣ Chief Taravana - Kapono Beamer [jellyfish follows SpongeBob]
‣ Hello Blues - Sage Guyton, Jeremy Wakefield [SpongeBob shows the jellyfish to Squidward]
‣ Stadium Rave A - Mark Governor, Glenn Nishida [dance music/Dance music again]
‣ Furtive Footsteps - Paddy Kingsland [more jellyfish arriving at SpongeBob's house]
‣ Stadium Rave A - Mark Governor, Glenn Nishida [dance music again]
‣ Row, Row, Row Your Boat - Brad Carow [Squidward playing clarinet]
‣ Stadium Rave A - Mark Governor, Glenn Nishida [dance music still playing]
‣ Death Trap - Gregor F. Narholz [jellyfish angry at SpongeBob]
• Jellyfish Jam (song) - Brad Carow [ending]
- This episode is available on the Sea Stories, Complete First Season, The First & Second Seasons, Movies & TV Collection, The Best 200 Episodes Ever, Rockin' Bikini Bottom, SpongeBob SquarePants Vol. 1, From the Beginning, Pt.1, First 100 Episodes, and Hall Monitor DVDs.
- Since 2012, airings of this episode on Nickelodeon have been shown without the title card, but instead cutting into the episode credits. Airings on Nickelodeon have also been slightly sped up (but not altering the pitch), likely for time limits. 
- There are 17 jellyfish on the title card.
- This is the first episode to use CG effects, like when SpongeBob's house jumps around and then pans over to Squidward's house.
- This is the second episode with jellyfish on the title card. The first is "Jellyfishing."
- This episode premiered in Canada on May 27, 2000.
- The alternating flashing lights seen in this episode during the disco are very fast and could have been a potential cause for seizures or other similar conditions to some people.
- Even though SpongeBob is able to sleep through the blasting music in his own house, Squidward is kept up all night by it.
- According to "Sailor Mouth," a dolphin noise represents a swear word which means if one would listen to the song "Jellyfish Jam" without this episode, it could imply bleeped-out swear words subliminally.
- The scene when Squidward plays his clarinet with a microphone which it blasted on SpongeBob's house became popular in various videos on YouTube and a fad.
- This is a rare time SpongeBob bluntly tells Squidward about his terrible playing of the clarinet, another time is in "The Camping Episode."
- In the Polish dub, this episode is titled "Imprezka z meduzami," which means "A Party with Jellyfishes."
- In the German dub, this episode is titled "Disco-Quallen," which means "Disco Jellyfish."
- In the Arabic dub, this episode is titled "اللخبطة قنديل البحر," which means "Snafu Jellyfish." "Snafu" is a word that means a confused or chaotic state: a mess.
- According to the Complete 1st Season Disc 1 description of this episode, the jellyfish in this episode are all male.
- This is the first episode to use the APM track "Chief Taravana."
- This is one of two season one episodes, along with "SB-129," with a small scene that tests digital ink-and-paint animation, as well as the first episode in the series to use it. In this case, the shot of SpongeBob standing on a hill in Jellyfish Fields with the jellyfish swimming was done digitally.
- This episode premiered on Sean Charmatz's 19th birthday.
- In a July 2019 airing, this episode was paired with the season 8 episode "Treats!" instead of the sister episode "Hall Monitor."
- "Stadium Rave" is very similar to "Get Ready for This," a song commonly played at basketball games.
- When Squidward says "SpongeBob is the only guy I know who can have fun with a jellyfish...for twelve hours!", the night stand with the lamp moves from the left to the right.
- When SpongeBob leaves his room when he wakes up, a portrait of him and Patrick can be seen. In the aforementioned portrait, the former is purple and the latter is mint green, unlike their usual colors.
- When SpongeBob wakes up to find the jellyfish gone, Gary is also gone. When he exits his bedroom, Gary follows him.
- When Squidward plays the clarinet out of the window, he is wearing his pajamas. However, after SpongeBob pops his head out of the window and says "I don't think the jellyfish like it," Squidward is seen wearing his brown shirt. Then after Squidward sets the speakers, he is wearing pajamas again. When Squidward goes to SpongeBob's house, he has his brown shirt on again.
- SpongeBob's living room is on the first floor, but when he pops his head out the window, telling Squidward to play his clarinet better, he appears to be on the second floor.
- Before SpongeBob says, "Gary, you were right. Thanks for not rubbing it in," Gary's mouth moves to "Meow" but no words or sounds come out.
- Throughout the episode, the texture of both SpongeBob and Squidward's houses changes. An example is once they become a lighter shade of their normal color.
- When SpongeBob and the jellyfish are dancing, the fish with the hook in the background's eye kept moving.
- Both SpongeBob and Squidward are stung by the jellyfish, but Squidward has painful welts from said stings, while SpongeBob does not (but he does from other episodes where he gets stung).