These very big, very hungry gastropods are the largest land snails on Earth. They can grow up to 8 inches long, with about a 4-inch diameter. That's roughly the size of the average adult's fist. They're also voracious eaters, known to feed on at least 500 types of plants. If fruits or vegetables are not available, the snails will devour whatever is available, including paint and stucco on houses. At least it’s a good thing they're vegetarian.