Damage = Reptile is a Continuous Trap Card.
Trap Cards are normally Set first and can be activated on a later turn, often in response to an action.
On the current TCG and OCG Forbidden & Limited lists tracked here, Damage = Reptile is Unlimited.
YGOPRODeck lists Damage = Reptile for these formats: Duel Links, Edison, TCG, OCG, Master Duel.
A listed print of Damage = Reptile appears in Ancient Guardians (ANGU-EN058) at Rare rarity.
Among markets shown on this page, the lowest listed snapshot for Damage = Reptile is about $0.06 on Cardmarket (prices change frequently).
