The ghost crab or sand crab, Ocypode quadrata, is a common shore crab in the eastern United States, where it is frequently seen scurrying along beaches between sunset and dawn.

These crabs are called ghosts because of their ability to disappear from sight almost instantly, scuttling at speeds up to 10 miles per hour, while making sharp directional changes. These creatures have two black eyes, with sharp 360 degree vision which they use to see flying insects and catch them in mid air. The ghost crab, however, cannot see directly up, so it must burrow into the ground to prevent birds from catching it.

The ghost crab tunnels down four feet into the ground at a 45° angle, creating 1-2 inch wide holes, which speckle the beach. At dusk, these crabs will sprint to the ocean in order to obtain oxygen from the water which washes over their gills, and in June, females will release their eggs into the ocean. Ghost crabs hibernate during the winter, holding their breath for six weeks, by storing oxygen in sacs near the gills.