The Dragon Jellyfish is a huge jellyfish with pink scales on his head, six long tentacle stingers, a barb, eight red polka dots, and a dragon tail. He is very powerful and has the ability to burn others and is also very fond of Krabby Patties. He was owned by Planktonamor until he stung him after tasting SpongeBob's Krabby Patties and switching sides.
The closest jellyfish in relative size to the Jellyfish Dragon is the King Jellyfish.
Just like his possible descendant, King Jellyfish, Dragon Jellyfish seems to be easily calmed down when given food, as he stopped his rampage after being given a Krabby Patty by SpongeBob, and the King Jellyfish stopped his rampage after SpongeBob gave his a bubble resembling a delicious pie.
List of places The Dragon Jellyfish has destroyed (as heard in one of Squidly's songs):