The Gold Throated Singer, is a rare kind of jellyfish that SpongeBob and Patrick encountered in the episode "The Pink Purloiner." It is gold, and has 5 stingers, one having a barb at the tip. It is only seen in Bikini Bottom, during the rare annual jellyfish migration through Jellyfish Fields. It sings in an opera sort of voice and can't sting. Its speed is based upon the pitch in which it is singing in, which makes it relatively hard to catch.
The jellyfish is obviously gold and can sing.
It is possibly the only jellyfish that actually can sing/talk.