Unbreathing Horde

Most creatures shrink as the game drags on and the board attrits away. This one runs the other direction: it counts every other Zombie you control and every Zombie card in your graveyard, then writes that total onto itself as +1/+1 counters, so the deeper the graveyard fills the larger it arrives. The 0/0 base means it is nothing without that count, a payoff rather than an opener. The second ability is the real twist. It survives on its counters instead of toughness: incoming damage is prevented and shaves a counter away, so a creature sitting on five counters effectively has five lives against damage, though each hit bleeds it down and the body never regenerates the loss. That defense is total against burn and combat and worthless against everything else. Destruction, sacrifice, and edicts all ignore the counter pile entirely and take the whole thing at once. That split is the tension worth playing around: enormous and nearly impossible to damage off the board, yet brittle to any answer that does not bother dealing it points. It converts every dead Zombie into stored toughness, which makes it a graveyard-tribal scaling threat: best deployed once the tribe has already accumulated, when the count is high enough to make the prevention clause mean something, and weakest the moment an opponent reaches for an unconditional kill spell.