The moon snail is a large gastropod found in many different colors. The snail has a big foot that is used for many things, to glide through the water, to bury itself deep into the sand, and to capture clams. They are carnivorous and eat mostly clams, if you ever find a clam with a perfect hole in its shell it was eaten by a moon snail. They are mainly found in sandy and muddy beaches all around the world, in warm and cold water. The moon snail is named after Meriwether Lewis who was the first one to find a moon snail at the mouth of the Columbia River. Some people even eat them! But most of the time people just enjoy to look at these bizarre creatures.
There are two common species of moon snails, there is the Atlantic moon snail and the Northern moon snail. Their behavior and structure are almost the same. The typical moon snail's shell can be about 5 inches in diameter, but with its foot it can be over 12 inches. This creature can fit its large foot completely into its shell.  They can be a number of different colors, in tropical areas they are usually colorful, but in colder waters they can be colored with pastels, brownish, or white.  The front of the snail's body has a large head shield that partly overlaps the shell, it has flaps on both sides of the body partially. The shell can come in different shapes from a spiral shell to a flattened shape. 
When it is breeding season, the females make a nest that is in the shape of a ring made up of sand grains which lines the many eggs. These things wash up on the beach a lot, and they look like collars so they are usually called "sand collars". During Spring and the Summer when there are low tides is the best time to try and find these. The female moon snail at that time comes up to the shallow water to lay her eggs. The eggs look like thin pieces of rubber. The eggs are protected and kept together with mucus.
The moon snail is usually found in low tides on beaches that have a lot of sand and/or are muddy. It spends most of the daylight hours underground, buried. During its first months it eats algae only, but once it becomes an adult, the moon snail mainly eats clams, the Little Neck Clam and the Butter Clam being its favorite, but it also eats cockles, horse clams, and sometimes other moon snails if they come across paths and it's hungry enough.  The moon snail suffocates its prey using its foot to wrap around it until it dies. Once that is done, the foot holds onto the clam and the moon snail secretes a chemical that softens up the shell. This process can take hours or even days depending on the shell's thickness. It drills a hole into the shell with its radula and then sucks out the meat inside.  They are eaten by humans, especially by Norwegians and Europeans, sea gulls, and sunflower stars. 
As A Cuisine
Some people not only look and observe moon snails, but they eat them. If you are going to eat one, the snails' meat should be raw. Sometimes you can remove the meat without hurting the shell, but you can also crack the shell with a hammer and remove the meat that way. If you want to save the shell, you have to carefully put a knife inside the shell's curve and then you have to cut the opening of the moon snail. If you cut it right, then the entire moon snail will just come out completely without complications. Then once the meat is out, there will be dark organs that you will want to take out, you will also want to cut off its head and operculum. To then preparing the animal, you want to cut it into steak sized pieces of meat, the meat will be very hard so you will probably want to use some tenderizing powder and then pound it. Then you have to put it in the refrigerator for a whole day for the powder to work. And then you can cook them any way that you would like.
- Naticidae Multiple authors. Wikipedia
-  Ronnie, 11/23/98.
- John Schaefer, Oregon Department of Fish and Wildlife, 1997.
-  Rudman, W.B., June 28th, 2001.