Wolf in Sheep's Clothing is a Normal 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, Wolf in Sheep's Clothing is Unlimited.
YGOPRODeck lists Wolf in Sheep's Clothing for these formats: Duel Links, Common Charity, Edison, TCG, OCG, Master Duel.
A listed print of Wolf in Sheep's Clothing appears in Stardust Overdrive (SOVR-EN069) at Common rarity.
Among markets shown on this page, the lowest listed snapshot for Wolf in Sheep's Clothing is about $0.05 on Cardmarket (prices change frequently).
