A picture of one of these will show up on the internet several times per year with claims that it came out of the sewer and is a huge alien creature. The top image was in English Russia today: "And caught one thing up then in big panic stepped away cause it tried to bite them so they had to kill it with some equipment and here are the remains of it. It was around 5 feet length."
It's only a triops (name means "three eyes" - which it has), also known as a "tadpole shrimp," a crustacean resembling a horseshoe crab. Like the horseshoe crab, it is a living fossil, having survived 70 million years. A full-size specimen is several inches long (see photo below - which shows the paired eyes + the one in between them).
The species is considered a human ally against the West Nile virus, as the individuals consume Culex mosquito larvae. They are used as a biological agent in Japan, eating weeds in rice paddies. In Wyoming, the presence of Triops longicaudatus usually indicates a good chance of the hatching of spadefoot frogs. Dried eggs of Triops longicaudatus are sold in kits to be bred as aquarium pets
...if humans do not devastate its habitat, the species may survive for another 500 million years.