Snake Rain is a Normal Spell Card.
Spell Cards are usually activated from the hand on your turn unless their type gives another timing window.
On the current TCG and OCG Forbidden & Limited lists tracked here, Snake Rain is Unlimited.
YGOPRODeck lists Snake Rain for these formats: Duel Links, Edison, Speed Duel, TCG, OCG, Master Duel.
A listed print of Snake Rain appears in Ancient Guardians (ANGU-EN051) at Collector's Rare rarity.
Among markets shown on this page, the lowest listed snapshot for Snake Rain is about $0.17 on TCGPlayer (prices change frequently).
