Crawlspace

Where Propaganda and Ghostly Prison tax attackers, this charges nothing and instead caps the swarm at two bodies, and that distinction is the whole design. A tax effect makes a wide board pay per attacker, so it bleeds token decks and punishes go-wide aggro for the cumulative cost; it folds, though, to a lone enormous threat that happily pays one toll to swing for lethal. The cap inverts that math. It is indifferent to how big the attacker is and indifferent to how much mana the opponent has: the third, fourth, and fifth creatures simply stay home, and no amount of mana buys them in. The cost of that clean limit is breadth. A single commander-sized threat walks right past it, and the two attackers that do get through can carry whatever evasion or trample they like. It is a hard limit on quantity, blind to quality, the precise mirror image of what the taxing enchantments handle worst. The flavor lands the mechanic exactly: a narrow corridor where only so many can come at you at once, and the rules text reads like the picture. As a colorless answer to creature counts rather than creature size, it occupies a more specific niche than the tax pieces it superficially resembles, a piece for the deck that fears the swarm and cares nothing for the spike.