A snail classifies as a gastropoda, which is a member of the mollusk family. Mollusks are defined by having no backbone, soft bodies and hard shells to protect the body. Both water and land snails are in the mollusk family.
Reptiles are cold-blooded animals that are either strictly carnivorous or omnivores. Snakes, crocodiles and turtles are examples of reptiles.
Garden snails and marine snails are not the only species in the mollusk family; other mollusks include clams, octopus and cuttlefish. Slugs identify as gastropods, even though they do not have a hard shell. A snail's shell is made of calcium carbonate, and the shell will grow along with the snail's body, until the snail reaches adulthood.