Blind Creeper

A 3/3 for two mana with a built-in self-destruct timer keyed to the one thing every game guarantees: people cast spells. Aggressive black beaters of this era leaned on this trade constantly, paying for an above-rate body with a downside the opponent could not always avoid, but this one is unusual in that you, too, trigger it. Every removal spell you point at a blocker, every pump you cast to push damage, shaves a point off the very creature you are trying to protect. The shrink is until end of turn, which means the body resets each turn back to its full size, so the penalty bites hardest in the busy turns when both players are dumping the hand and the board is most contested. That is the tension the design is built on: a clock fast enough to demand interaction, an ability that punishes the interaction it provokes, and a controller who has to weigh whether casting a spell of their own is worth softening their own attacker. It is a creature that wants the game quiet and your hand empty, which is precisely the opposite of how a tempo-minded black player tends to operate.