Ghost crabs are really neat. They can move at speeds of up to 10 miles per hour and they live in burrows they build in the beach sand. Those holes can go down as deep as three to four feet, where they will hibernate during winter. Their two eyes allow them to see 360 degrees simultaneously, although they cannot see directly above them. They are called ghost crabs because they are so elusive, often not giving people much of a chance to see them as they move across the beach.
Here's a picture of a ghost crab taken on Daytona Beach Shores yesterday, along with a video.