Granite Witness

Set it down face down and it reads as a nondescript 2/2 with ward, one of a dozen possible flip threats an opponent has to price into every attack and block. But the reveal does more than change the body: turning it face up lets you tap or untap a creature, and that clause is what makes the bluff pay. Flip mid-combat to untap your best blocker after attackers have committed, or tap down a defender to shove damage through, and the disguise cost has bought you a combat trick welded to a permanent instead of a one-shot spell. Vigilance on the revealed flier matters more than it looks: the body keeps attacking without giving up the defensive stance that makes the untap-a-blocker line worth setting up. The gargoyle-detective flavor rides the mechanic cleanly, a stone figure that looks inert until it moves, which is exactly the misread a disguised creature is asking for. What distinguishes this from most morph-style bluffs is that the payoff usually lives entirely in the surprise of the flip; here the free tap or untap reshapes a combat step you were already choosing to enter, so the information game and the board game reward the same decision at the same moment.