Big Lenny is a large and dangerous jellyfish, and one of the only known jellyfish to actually kill its stinging victims. As SpongeBob revealed in the episode I'm Your Biggest Fanatic, Dr. Manowar is the only fish who has survived an attack by Big Lenny, getting by only with a huge bump that hurts when anyone touches it.
Not much is known about Big Lenny since it is only shown in the episode I'm Your Biggest Fanatic however, we do know it has an evil, humanoid face. Big Lenny is obviously a very dangerous creature, because the lump on Dr. Manowar's face is very large. He also screams quite loud when Patrick touches it which implies that it hurts a lot.
- Big Lenny has never made a true appearance in the series.
- Dr Manowar's name is a refference to a Portugese Man O War.
- Unlike other jellyfish stings, people can die if stung by Big Lenny.
- It has never been seen in places like Jellyfish Fields, so it probably lives in a prison, a safekeeping area or in a jellyfish field too dangerous to jellyfish.
- The only time it was seen in Jellyfish Fields is in the game Operation Krabby Patty.
- He may be a Portuguese man-of-war or an Australian Box Jelly (For its deadly stings) or even a Lion's mane (For its size).