Eve Dickinson was going for a walk on the beach with her husband and two children in Auckland, New Zealand, when she came upon something strange.
On first glance, it may have looked like a huge discarded Jell-O mold, but it was actually a type of jellyfish called a lion's mane jellyfish.
Dickinson's son said the jellyfish reminded him of a volcano, according to Stuff. Indeed, it did seem to have a cauldron-like center that even appeared to be bubbling up like lava. The jellyfish was also almost perfectly circular, sprawled out on the sand.
This is what a lion's mane jellyfish looks like when it's in the water:
Jellyfish are about 95 percent water, so the shape of their bodies can change quite a bit when they wash up on beaches and start to dry up.
The lion's mane jellyfish is the largest species of jellyfish in the world.
They are typically about 20 inches in diameter, but there have been sightings of individuals that are three feet in diameter.
This photo of Dickinson's children with the jellyfish shows about how big it was:
Lion's mane jellyfish are quite common in New Zealand, but they typically only wash up during the plankton blooms that happen in warmer months. Since New Zealand is in the southern hemisphere, it's currently transitioning from winter to spring. September is early for a lion's mane jellyfish to make an appearance.
The family saw many jellies on the beach that day but only one lion's mane. They actually turned the other ones over to see if they had the same volcano-like appearance, but none did.
Stings from lion's mane jellyfish can cause welts, but are not deadly. Their tentacles could still sting after they've washed up on a beach, so if you encounter one, proceed with caution.