Koskun Falls

At the beginning of your upkeep, sacrifice this enchantment unless you tap an untapped creature you control. Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6o28gb0bj1pb1hobje1wv3.