SpongeBob is out jellyfishing in Jellyfish Fields. He catches a jellyfish, gently tickles out some of its jelly, and lets it go, naming it "Twelvy" on its way. He then spies a very rare blue jellyfish, the only jellyfish in the field he has never been able to catch and name. SpongeBob's attempt to catch this specimen ends in failure once again.
Later, SpongeBob goes on his five-minute lunch break at the Krusty Krab, and puts the fresh jellyfish jelly on a Krabby Patty. A customer is eager to try the jelly-covered patty, so SpongeBob provides him with a dollop. Amazed with its taste, the customer sings a song proclaiming its greatness and plops jelly on the patties of all the other customers, who enjoy it as well. Mr. Krabs, who at first reviles the thought of altering the patty's recipe, soon sees the potential profit and officially puts the new Jelly Patty on the menu.
To his great delight, SpongeBob is tasked to go out and gather as many jellyfish as he can, though he asks Mr. Krabs to keep the jellyfish comfortable while milking them for jelly. He continues to catch jellyfish, and Mr. Krabs continues to demand more, until Jellyfish Fields is completely deserted. SpongeBob concludes that there are no more jellyfish to catch, and begins to walk home.
Something seems to be following him, however, and upon arriving home, SpongeBob ends up captured in a jar himself by the blue jellyfish. It then takes SpongeBob to a secret factory farm, where he discovers that Mr. Krabs is forcefully wringing every jellyfish dry to increase his bottom line. Realizing Mr. Krabs' unscrupulous plan, SpongeBob angrily confronts him and declares his intention to free the jellyfish, but is unable to open the door to their cage.
Mr. Krabs laughs and boasts of his sturdy voice-activated door that only opens when he says, "Open," which ends up opening the door. The freed jellyfish swarm over Mr. Krabs and give him a mighty zap before flying off. Thoroughly charred, Mr. Krabs meekly decides to take jelly off the menu. Spongebob vows to never again let his net be used for anything except catch and release, prompting the blue jellyfish to gently enter his net, allowing itself to be caught. Touched, SpongeBob decides to call the jellyfish "Friend," and they share a slightly shocking handshake.
In the Fisher Price Interact TV version of this episode, the scenes when No Name makes the power in SpongeBob's house go out and when SpongeBob says goodbye to Twelvy were cut.
This episode was featured in the SpongeBob Earth Day Marathon that leaded up to the premiere of "SpongeBob's Last Stand" and the story in that episode is similar to this episode.
The French Narrator mentions the episode title when he says "Ahh, another beautiful day in Bikini Bottom's own Jellyfish Fields. An untamed world of natural order where the little jellyfish jellies roam free across the salty seascape. And where there is jellyfish, there is the Jellyfish Hunter."
The scene where Mr. Krabs said "More!" and looked very morbid has become an internet meme. This meme is known as "Moar Krabs."
In the UK, the shot where No Name cuts the power to SpongeBob's house is replaced with a shot on the door outside of SpongeBob's house at night.
This is the first episode to show Mr. Krabs as the main antagonist.
When Mr. Krabs is riding the bicycle, he wears his headphones on the sides of his eyes which may hint that his eyes and ears may be connected.
This is the sixth episode to feature the Krusty Krab without Squidward, although he is mentioned.
SpongeBob picking up the phone and hearing heavy breathing is a reference to the 1979 movie When a Stranger Calls.
When No Name/Friend sneaks into SpongeBob's house, he looks like a blob crawling around the floor. When he does this, he resembles ChuChu, a character from the video game Kirby's Dream Land 3.
When SpongeBob takes off and rockets are activated where his legs are, his pants drop off. This is referenced to booster stages in rockets built by NASA.
The way the jellyfish are treated in the factory is a reference to factory farming, particularly with the poor ethical treatment to animals.
When SpongeBob is only wearing underwear in Jellyfish Fields, his sleeves are still shown.
After Fred finishes his song, you can hear the crowd cheer for him, however, none of the fish are moving at all and only the cheering sound is heard.
When SpongeBob is being followed by the blue jellyfish, he says, "It feels like somebody... wants to sell me something!" However, the closed-captions read "tell" instead of "sell."
When Mr. Krabs says "The door will only open if I say open." It only opens the second time he says the word.
It could possibly be that it only activates when the word "open" is said clearly and loudly, as Mr. Krabs said "open" in a more defined way the second time, and if the door is voice activated, then Mr. Krabs' voice would have needed to be recorded, and he would have recorded it in a clear way.
During the part where Mr. Krabs says "You'll never catch me!," his walkman can be seen in his pocket; then, after the scene zoomed out, his walkman in his pocket is gone.
The closed-captions misspell "Krabby Patty" as "crabby patty."
In the German version, SpongeBob says "Let me out!" in English untranslated.