Moon snail

Some locals call these Tiger Eyes. I prefer to call them by their real name: Moon Snails. These are some of the most common shells I've found on the beach.

Moon Snails are carnivorous, tracking down their prey and drilling a hole through the poor animal, (usually another mollusks, and even other moon snails), with its tubular proboscis. (A proboscis is sort of like an elephant's trunk.) This explains all of those shells on the beach with a several-millimeter-wide hole in them, as well as Moon Snails themselves, since they're cannibalistic.

Oh, and one other thing. Have you ever seen those wierd sandy-colored collar-like things on the beach? At this time of year there are tons of them. Those are Moon Snail eggs. The exact recipe is Moon Snail slime, eggs, and a whole lot of sand. These collars dry out on the beach and crumble, and then high tide takes them back in. :)