A slug on a wall in Kanagawa, Japan. Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc. The word slug is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a small internal shell, particularly sea slugs and semi-slugs (this is in contrast to the common name snail, which applies to gastr
![Slug - Wikipedia](https://cdn-ak-scissors.b.st-hatena.com/image/square/9db8379362b1b1b8de280f680e5e050ea530a542/height=288;version=1;width=512/https%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2Fd%2Fd7%2FSlugs_1896.png)