Evolutionary Leap

The mana sink that turns a board of expendable bodies into a fresh creature every turn. The cost structure is what makes it tick: paying green and sacrificing a creature, repeatable, means any deck with a way to refill the battlefield (tokens, recursion, cheap bodies that were going to die anyway) gets to convert one creature into a draw-toward-creatures while feeding death triggers along the way. But the dig stops at the first creature card revealed: you take whatever surfaces, not whatever you want, with the noncreature cards above it filtered to the bottom of the library in random order. That randomized bottoming is the catch, not flavor; you cannot stack your library afterward, so what you keep is simply the next creature down. The filtering past lands and spells is genuine card selection rather than a tax, which is the quiet upside the headline "trade a creature for a creature" undersells, but the lack of control over which body you find means the engine wants a deck built so thick with redundant, interchangeable creatures that whatever appears is acceptable. That dependence on critical mass makes it a poor fit for the lean, low-creature piles other card-advantage enchantments slot into; this one wants a battlefield it can keep eating and rebuilding. It sits in green's long line of "creatures as a renewable resource" engines, the effects that let a sacrifice loop replace cards rather than just generate mana or damage, and it pulls double duty in any shell that cares about creatures entering and leaving play.