Mystic Familiar

Threshold pays out twice here, and that doubling is the whole point. With an empty bin in the early turns, this sits as an unremarkable 1/2 flier, a body a graveyard deck tolerates while it does its setup work. Cross seven cards in the yard and the creature becomes a 2/3 with protection from black, and in an era built around black removal and black-based midrange, the protection was the upgrade that actually mattered: it blanks instant-speed kill spells, walks past black blockers, and carries an aura or equipment through the one color positioned to answer everything. The design is honest about what that protection costs. The keyword only switches on once the controller has done the milling, discarding, and trading that threshold demands, so a genuinely strong defensive clause is gated behind a board state the deck has to earn rather than simply assemble. The structure (a creature whose stat line and keyword profile both flip the moment a graveyard count is met) is the template threshold returned to repeatedly, and white's version leans on the part it does best: evasion plus a targeted protection clause that does more work than the single point of power the upgrade adds.