Snail

Snail is a common name for  gastropod molluscs  that can be split into three groups, land snails, sea snails and freshwater snails.

Description
The common Garden Snail is one of the most successful invertebrates on the planet, colonising entire continents despite its apparent vulnerability. Though it is a slow, soft creature, it is able to protect itself by withdrawing into its tough shell, which shields it from predators such as birds or ants. Furthermore, when wounded, its gelatinous form has the ability to restore such damage, even allowing the Snail to re-grow lost eyes or organs. The Snail is a very cheap unit with obvious defensive capabilities that are able to come into play rather early on in games-naturally, this gastropod's speed is a negative factor, so combine the Snail with a faster creature for best results.