Phytohydra

That 1/1 body is bait. The replacement effect converts every point of damage into permanent +1/+1 counters, so the creature answers a burn spell by growing the exact amount it was meant to die from: aim three damage at it and you have spent your removal turning it into a 4/4. The point is that the Hydra inverts an entire category of answers against itself. Damage-based removal feeds it, ground combat feeds it (block or get blocked, and the combat damage that should have traded becomes counters), and even the controller's own sweepers and pingers fatten it rather than kill it. Anything that routes around damage entirely (a destroy effect, an exile, a sacrifice, a toughness-shrink, a bounce) still works cleanly, which pushes the opponent off their reflexive tools and toward the ones that do not deal damage at all. It belongs to the lineage of damage-prevention-as-growth creatures, but where most of that family caps the conversion or fires once, this one has no ceiling: it scales with whatever anyone commits to it, opponent or pilot. The catch is on offense, where a 1/1 with no evasion and no haste threatens nothing on its own; the counters arrive when something interacts with it, not when it attacks into open air. It punishes the instinctive small-creature kill spell that a green-white body this fragile seems to invite, and rewards a board state busy enough to keep throwing damage at it.