Molimo, Maro-Sorcerer

Maro is the named ancestor here: a green creature whose size is dictated by a counted resource rather than a printed number, and the lineage Wizards keeps returning to. The original Maro tied itself to hand size, a fragile peg that empties as you cast. This redraw moves the count to lands, which is the green resource you most want to accumulate anyway and the one that almost never shrinks. The size grows on the same axis the deck already builds toward: every land drop adds a full point to both power and toughness, and ramp turns it monstrous without asking for a single extra card. Trample is the keyword that converts that growth into a clock, since a creature this large is otherwise easy to chump indefinitely. Note the math built into the cost: paying honestly usually means you already control seven or more lands, so it often lands as a 7/7 or larger the turn it resolves, no setup required. The fragility lives elsewhere, in the cheat: animate or reanimate it onto a thin board and the same land-as-counter logic that makes it enormous on curve leaves it small enough to die to damage. Green has reworked that land-as-counter idea many times since, in animation effects, in dryads, in elementals that read off your battlefield, but the version that simply equals your land count, trample and all, still states the idea with nothing else getting in the way.