Sabertooth Mauler

Most attack-and-grow creatures grow only when they connect, and they tap out to do it. This one flips both terms of that bargain. The end-step check asks only that a creature (any creature, yours or theirs) died during the turn, and it pays with a permanent +1/+1 counter and an untap. The untap is the quieter half of the design: the Mauler can attack, weather the turn in which a trade or a block or a sacrifice happens, and still stand ready to block on the crackback. That reframes a repeatable sacrifice loop or a grindy board stall from a race the creature has to win into a steady enlargement engine that never lowers its guard. The 3/3 body is the floor: on a turn where a token is sacrificed or an attacker trades in combat, it wakes up the following end step as a vigilant 4/4, and where bodies die every turn the counters accumulate faster than most single-target removal wants to keep pace with. Because the death need not be your own, it slots as a common-rarity payoff for both sacrifice decks and go-wide green: it sits inert on an empty board and quietly runs away with any game that keeps feeding the graveyard.