Snails are fairly cheap and easy to maintain as pets, though you have to be careful of releasing them into the wild because someone could step on them or get caught by predators.
A special case is Giant African Snails which can not be released into the wild at all; they can cause ecological havoc due to their great devastating power, especially for agriculture. If you have or found one, contact the Animal and Plant Health Inspection Service (APHIS).
As for raising a pet snail you would need:
- A wide transparent and well-ventilated tank.
- Soil or compost.
- A stick or log.
- Plant pot
- Fresh apples
- A bowl of water to drink and bathe.
- A Water spray gun to keep the tank moist.