Horseshoe Crab from Thailand

With seven pairs of legs, nine eyes, and shells the shape of flying saucers, horseshoe crabs look like aliens from the deep.
(Image Courtesy Paulo Bernardino Ribeiro)

With seven pairs of legs, nine eyes, a tail with light-sensing organs and shells the shape of flying saucers, horseshoe crabs, like this species from Thailand (Tachypleus tridentatus) look like aliens from the deep. They are not actually related to crabs, but to arachnids (spiders, scorpians and ticks).