Krakilin

Green's X-creatures are one of the color's oldest pricing experiments: scale the body to the mana, then decide what the floor and ceiling should be. The structural answer here is the regeneration clause. A vanilla X/X for two-plus-X is a fair rate, but it dies to any removal spell or unfavorable block, which makes the X investment a liability rather than a payoff. Bolting in regeneration changes the math entirely: the counters are permanent, so once they land you can protect them for one green and a generic mana, turning a fragile mana sink into something that demands repeated answers or a sweeper. The design tension is between the front-loaded commitment (every point of X is spent the turn it enters) and the back-loaded insurance (the regeneration stays cheap enough to use all game). Size is a one-time decision; survival is an ongoing one. The 0/0 base loaded with counters rather than a flat X/X body is the tell of an era still working out how to template scalable creatures, and that choice quietly opens interaction with anything that cares about +1/+1 counters being present rather than just a printed power and toughness.