The Queen jellyfish is a giant female jellyfish that is the ruler of all the jellyfish, along with her husband, the King jellyfish. She first appears in the episode "Jellyfishing."
The Queen Jellyfish looks like a regular jellyfish, except she is much larger. Her sting is also much more powerful. From "I'm Your Biggest Fanatic" onwards, she is depicted wearing a crown embedded with jewels. She has six large dark magenta spots and seven tentacles.
She appears to be mean or at least protective when it comes to the other jellyfish, and she does nit like it when people bother her children, making her aggressive towards a person.
SpongeBob and Patrick take Squidwardjellyfishing. He finds a jellyfish and tracks it until it lands on the Queen jellyfish. Squidward does not know that it is the Queen jellyfish. He catches the jellyfish and in victory, he repeatedly hits the Queen jellyfish until she gets up. She goes over Squidward and he "runs" away. Eventually, it ends with her zapping him.
At the end of the episode, she returns after being summoned by the same jellyfish from the previous day and zaps Squidward again.
"I'm Your Biggest Fanatic"
In Jellyfish Fields, after SpongeBob passes all of Kevin C. Cucumber's tests, he says that they are going to catch the Queen jellyfish as SpongeBob's final test. It should be noted that he actually says "a Queen Jellyfish," not "the Queen Jellyfish." This means that there are other female jellyfish crowned queen.
SpongeBob is then used as a bait for the jellyfish. He claims that he has never seen a Queen jellyfish before. The Jellyspotters leave, and for hours, SpongeBob calls for the Queen. When he gives up, he notices what he thinks is the Queen Jellyfish. Later, SpongeBob finds out that it is a mechanized jellyfish and what the Jellyspotters' true intentions were. They make fun of him and the King jellyfish arrives. He thinks that it is the real Queen jellyfish, only to later find out that it is not.
After SpongeBob saves the day, Kevin says that SpongeBob is still not a member of the Jellyspotters because he did not catch a Queen jellyfish. The other Jellyspotters take off Kevin's "crown" and give it to SpongeBob, making him a member. The "crown" was actually just Kevin's head.
She is in Rock Bottom and has found one of the Flying Dutchman's treasure keys, which SpongeBob needs. However, the Queen jellyfish is being pestered by two tiny Dirty Bubbles, so the player has to hit her with some water balls until the Dirty Bubbles leave her alone. She will then leave Rock Bottom and will leave the treasure key for SpongeBob to collect.
SpongeBob's Atlantis SquarePantis
She reappears in the DS version, where she acts as a boss. After stealing Squidward's clarinet, she retreats to Mu's temple, where two of the playable characters will fight her. Throughout the fight, she will try to charge into them, electrocute them, and spawn other jellyfish to damage them. She can only be damaged by picking up the rocks that fall from the ceiling and throwing them at her.
After defeating her, she deflates to the size of a normal jellyfish and leaves Squidward's clarinet behind.