Icefall Regent

Flying When this creature enters, tap target creature an opponent controls. That creature doesn't untap during its controller's untap step for as long as you control this creature. Spells your opponents cast that target this creature cost {2} more to cast.

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6o73q249evpb1hxc9s9dej.