Encyclopaedia of Cryptozoology
Giant jellyfish
Giant jellyfish Coudray

Depiction of a hypothetical giant jellyfish by Philippe Coudray in Guide des Animaux Cachés (2009).

Classification Cnidaria
Proposed scientific names
Other names
Sea reported Atlantic Ocean, Pacific Ocean
First reported 1953
Prominent investigators Gary Mangiacopra
Karl Shuker

Giant jellyfish are cryptid giant invertebrates reported from the world's oceans.[1] The largest known jellyfish is the lion's mane (Cyanea capillata) of cold northern seas, but significantly larger specimens have occasionally been reported from temperate and tropical waters.[2][3] A distinct group of unnamed cryptid marine invertebrates, usually lumped together with giant jellyfish,[4] are very large, shapeless animals, seen mainly in the Pacific Ocean, which have been reported to prey on sharks. These are sometimes explained as actual giant jellyfish, not all of which possess the famous long tentacles,[2] but other theories have been proposed.[5]



A well-known encounter with a giant amorphous sea creature, sometimes referred to as a giant jellyfish, was allegedly made by an Australian diver in the South Pacific in 1953.[primary source needed] The case was first chronicled in the literature by Eric Frank Russell in his book Great World Mysteries (1967), but Russell's source is unclear.[6] According to Russian works, the diver was named Christopher Loeb or Christopher Loupa (Cyrilic: "Кристофера Лоупа"), and his story was published in an undisclosed newspaper.[5] The diver was testing a new deep-sea diving suit design when he allegedly saw the creature rise out of deeper water to paralyse and kill a large shark.[7]

All the way down I was followed by a fifteen foot shark which circled around full of curiosity but made no attempt to attack. I kept wondering how far down he would go. He was still hanging around some thirty feet from me, and about twenty feet higher, when I reached a ledge below which was a great, black chasm of enormous depth. It being dangerous to venture farther, I stood looking into the chasm while the shark waited for my next move.
Suddenly the water became distinctly colder. While the temperature continued to drop with surprising rapidity, I saw a black mass rising from the darkness of the chasm. It floated upwards very slowly. As at last light reached it I could see that it was of dull brown colour and tremendous size, a flat ragged edged thing about one acre in extent. It pulsated sluggishly and I knew that it was alive despite its lack of visible limbs or eyes. Still pulsating, this frightful vision floated past my level, by which time the coldness had become most intense. The shark now hung completely motionless, paralyzed either by cold or fear. While I watched fascinated, the enormous brown thing reached the shark, contacted him with its upper surface. The shark gave a convulsive shiver and was drawn unresisting into the substance of the monster.
I stood perfectly still, not daring to move, while the brown thing sank back into the chasm as slowly as it had emerged. Darkness swallowed it and the water started to regain some warmth. God knows what this thing was, but I had no doubt that it had been born of the primeval slime countless fathoms below.


Fortean researcher Richard Winer (1925 – 2016), best known for his interest in the Bermuda Triangle, wrote of seeing an enormous jellyfish-like animal, at least 50 ft (15 m) in diameter, south of Bermuda in his book The Devil's Triangle (1974). At the time, Winer was performing oceanographic work for General Electric, alongside a diver named Pat Boatwright, and was engaged in filming buoys underwater; however, by the time the jellyfish appeared, he had allegedly used up his camera film.[8]

I had just finished filming the movement of an instrumentation buoy in rough seas. The last of my film had run through the camera when my safety diver, Pat Boatwright, grabbed me by the shoulder and pointed downward. It was late in the afternoon, and the rough seas were distorting the light that penetrated into the depths. What I saw was phenomenal. How deep it was or its size I couldn't tell. It might have been 100 feet beneath us–maybe 150 feet. Its size I could only guess at–maybe a hundred feet across, possibly seventy-five, but no less than fifty feet in diameter. It was perfectly round. Its color was a deep purple. It was moving slowly up toward us. At its outer perimeter there was a form of pulsation, but there was no movement of water. As we started for the surface, it stopped its ascent. Then slowly it began to descend into the blackening depths. Awestricken, we watched until it was no more.
Bermuda jellyfish

Winer's sketch of the animal, as redrawn by Gary Mangiacopra.

Later, after observing swarms of much smaller jellyfish in the Marshall Islands, Winer concluded that the larger animal had been a giant jellyfish.[8] However, Boatwright believed it could have been a giant squid,[9] and, in light of the poor viewing conditions, Michel Raynal has suggested that it was a gigantic octopus, similar to the lusca, or even a tightly-packed shoal of small fish.[10] Winer revealed more details, published alongside a sketch of what he saw, in an interview with Gary Mangiacopra two years later. The alleged observation occurred in November 1969, at a depth of 30–40 ft (9–12 m), and lasted for around four or five minutes. The pulsating "outer perimeter" of the animal was pink.[9]


An anonymous user claimed on an early online newsgroup that a friend of his, working as an undersea welder in the Gulf of Mexico during the 1970s, reportedly often saw strange giant invertebrates, including "giant headless glowing living firehoses," as well as an undescribed predator which fed on the "firehoses". Chad Arment contacted the user for further information, and was told that the welder in question was named George Hale, and that he had died in 1994. Hale could not properly describe the predator, but it was supposedly built like a starfish or Hydra.[11]

My friend George Hale was unable to describe the predator in detail. It was too big and too close to him. It was as big to him as you are to an ant. As a matter of fact, he had to ascend PDQ because he was in fear of being crushed like a bug. But the predator had a pallor and skin texture like a sea anemone and it might have been built along the lines of a starfish or a freshwater pond hydra. And it was eating the firehose entity by swallowing it. It's [sic] method of propulsion is a mystery.

Other sightings[]

According to Russian sources, at least two other sightings of the amorphous sea monster have been reported in local newspapers. Members of a Chilean hydrographic expedition to the South Pacific in 1968 told the press that they had seen an animal which resembled the Australian diver's "black mass," near an abyssal trench.[5][primary source needed] A fatal encounter with such an animal allegedly occurred off Thailand in 2005, when a French scuba diver named Henri Astor told the press that he had observed a very large "strange brown mass" paralysing and killing a shoal of fish. Astor's unnamed companion allegedly disappeared after attempting to follow the entity.[5][primary source needed]


Lion's mane jellyfish

The lion's mane jellyfish (Cyanea capillata) of the northern seas is the largest known species of jelly (CC BY 4.0).


Deepstaria enigmatica

The "black masses" seen mainly in the Pacific may resemble large, shapeless jellyfish such as Deepstaria enigmatica.

The largest known species of jellyfish is the lion's mane jelly (Cyanea capillata), which is found in the temperate to cold waters of the Northern Hemisphere. A record specimen examined by Alexander Aggasiz (1835 – 1910) in Massachussetts Bay had a bell diameter of 7 ft 6 in (2.3 m), and tentacles 120 ft (36 m) long.[12] Rumours of much larger specimens, with tentacles estimated at 275 ft (83 m) in length, have come out of Arctic waters, and Jon Malakia of west Greenland testified under oath that he had seen an example with a bell width – rather than diameter – of more than 8 ft (2.4 m).[13] These are described merely as unusually large specimens of the known species, although the Arctic variety was formerly classified as a distinct species, Cyanea arctica.[12] Despite biomechanical limits, Gary Mangiacopra argues that much larger, scientifically-undescribed types of jellyfish are theoretically possible.[9]

Sightings of giant jellyfish have occasionally been explained as mistaken views of giant squid,[9] and some have theorised that the Australian diver's monster was an undescribed species of deep sea gigantic octopus.[6] However, Karl Shuker argues that this amorphous animal is more likely to have been a giant cnidarian. The diver did not espy tentacles, and, while all cephalopods possess limbs, some jellyfish, particularly deep sea species, do not show tentacles. The sudden paralysis of the shark could be explained by the venomous stinging cells of a giant jellyfish; such cells occur on the body as well as the tentacles. Shuker specifically compares the cryptid to the moon jellyfish (Aurelia aurita)[2] and the more shapeless Deepstaria enigmatica.[14]

Notes and references[]

  1. Shuker, Karl P. N. "A Supplement to Dr Bernard Heuvelmans' Checklist of Cryptozoological Animals," Fortean Studies, Vol. 5 (1998)
  2. 2.0 2.1 2.2 Shuker, Karl P. N. "Giant Jellyfish," Fate, No. 47 (March 1994)
  3. Shuker, Karl P. N. (1997) From Flying Toads To Snakes With Wings, Bounty Books, ISBN 0-7537-1305-5
  4. Eberhart, George M. (2002) Mysterious Creatures: A Guide to Cryptozoology, ABC-CLIO, Inc., ISBN 1576072835
  5. 5.0 5.1 5.2 5.3 Vilenov, Vladimir (2010) Tayny Chetyrekh Okeanov
  6. 6.0 6.1 "An Octopus in the Hand...," The INFO Journal, Vol. 2, No. 4 (1972)
  7. Russell, Eric Frank (1967) Great World Mysteries
  8. 8.0 8.1 Winer, Richard (1974) The Devil's Triangle
  9. 9.0 9.1 9.2 9.3 Mangiacopra, Gary "A Monstrous Jellyfish?," Of Sea and Shore, Vol. 7, No. 3 (Autumn 1976)
  10. Raynal, Michel "The Case for the Giant Octopus," Fortean Studies, Vol. 1 (1994)
  11. Arment, Chad "Strangest of All," North American BioFortean Review, Vol. 2, No. 2 (2000)
  12. 12.0 12.1 Wood, Gerald L. (1972) The Guinness Book of Animal Facts and Feats
  13. Sweeney, James B. (1972) A Pictorial History of Sea Monsters and Other Dangerous Marine Life, Bonanza Books
  14. Shuker, Karl P. N. (16 September 2012) Nandi Bears and Death Birds - My Top Ten Deadliest Mystery Beasts karlshuker.blogspot.com [Accessed 18 January 2022]