Pyre Spawn

The 6/4 body is the tell: high enough to threaten a real clock, brittle enough that any respectable removal spell trades down against it, and that trade is exactly the point. This is a creature built so that killing it costs you something. The death trigger dealing 3 to any target means removal is never clean; block it and lose a smaller creature, chump it into the ground, or point a burn spell at it, and it still lands three damage on the way out, at the face or at whatever else needs answering. Left alone, six power ends the game quickly; dealt with, it takes a card and a life-total dent with it. Red aggression has always understood that a threat is best when the opponent's answer to it doubles as a cost. What separates this from the finishers that simply demand an answer is that the answer is never free, so the tempo math never fully favors the defender. It asks for a heavy investment (six mana is real), and the payoff is that it is durable in the only sense that matters for a beater: durable against being profitably removed. The value it extracts on death makes it a poor blocker to attack into and a poor threat to trade with, which is precisely the corner it wants to back an opponent into.