Bloom Hulk

Proliferate needed a body, and this is the plainest possible answer to what that body should cost: a 4/4 for four with the mechanic bolted to its entry and nothing else on the sheet. The green statline is the giveaway. Proliferate leans blue-and-artifact at heart, tied to counters that pile up on planeswalkers, +1/+1 grids, poison, and charge counters, but green is where you find the most efficient beaters, so handing green a stock-sized creature that also advances every counter already on board is a way to attach the mechanic to an aggressive shell without paying a premium for it. The design tension is that proliferate does nothing on an empty board: the enters trigger is entirely contingent on what you built around it, so this is a 4/4 with upside in a counters deck and a 4/4 with a wasted trigger everywhere else. That contingency is exactly why the rate stays fair. A creature that reliably bumped a superfriends board, refilled a Hardened Scales pile, or pushed a poison clock a step closer to lethal, every single time, for four mana, would carry a higher price; this one earns its modest slot precisely because the payoff is capped by whatever counters are already in play. It is the enabler-shaped creature: unremarkable on rate, meaningful only in a deck that has already committed to the axis it feeds.