Gluttonous Cyclops

Thirteen mana across its lifespan before it does the work of a six-mana card: pay for a 5/4 that trades down or chumps, then sink another to push it to an 8/7. The math is the whole tension. Monstrosity exists to hand the late game a mana sink that does not clog the hand, a way for a flooding deck to convert excess lands into board presence, and this is the keyword at its most stripped-down: no enters-the-battlefield trigger when it grows, no fight, no scry, just a body that gets bigger. The payoff for the second mana investment is an 8/7 with no evasion and no protection from the removal that was going to kill the 5/4 anyway, its monstrosity spent and offering nothing further once the counters land. That bluntness is the point of the design slot it fills, the common-rarity ceiling that teaches the keyword without warping anything around it: monstrosity as a clean mana sink for a creature meant to be a fine body first and a payoff second, the version of the mechanic you build a set's teaching curve around rather than a constructed deck.