We can assume, as a Jellyfish monarch, he leads the colonies of Jellyfish throughout Jellyfish Fields, presumably as a queen bee leads its hive.
He also despises Kevin, possibly because Kevin invented jellyfish oinment, and has an appetite for pie.
The King Jellyfish is a huge purple Jellyfish, bigger than any other one, and boasts a red royal robe fluffed with the wite and fuzzy and a golden crown.
- According to Kevin, the King's binomial nomenclature (Latin genus/species) is "Cnideria rex".
- The King Jellyfish is the only Jellyfish to ever speak true English, saying "Kevin!", "Mmm!", "What the...?" and "Yummy!".
- The King Jellyfish appears as the first boss of the video game Battle for Bikini Bottom.