Karlov Watchdog

Read the middle line and you know exactly which room this Dog was bred to police. A murder-mystery era leaned hard on face-down permanents (disguise and cloak, cards that hide their identity until their controller pays to reveal them), and this creature exists to jam that entire subsystem on your clock: an opponent's face-down permanent can't flip up during your turn, which means no surprise blocker growing to size, no ambush trigger firing mid-combat, no hidden threat unmasking to trade with your attacker. It is a hate piece pointed at a mechanic rather than a color, and outside a table full of disguised permanents that clause is inert text. What saves it from doing nothing is the third line, which quietly aims it at go-wide white aggro: attack with three or more and the whole board grows, a repeatable anthem gated behind a board state you were building anyway. Those two abilities pull toward opposite decks. The face-down denial wants a narrow, reactive matchup; the mass pump wants a proactive creature swarm. Stapling both to a vigilant 3/2 is the reconciliation: vigilance lets it commit to the +1/+1 trigger and still hold the fort, so the aggressive half never fully sidelines the defensive half. A creature engineered to answer one era's central mechanic while carrying just enough evergreen upside to survive that mechanic's departure.