Hidden Guerrillas

Part of an early-era cycle of one-mana green enchantments that lie inert until an opponent commits to a specific strategy, then convert for free into a creature. This one watches for artifact spells, and in the era it emerged from, artifacts were a near-certainty rather than a corner case. The wager is on your opponent's deck, not your own play: you pay for a permanent that sits as a blank green enchantment, and you collect a 5/3 trample body the instant they cast the artifact they were always going to cast. The conditional is what balances the rate. A player not leaning on artifacts simply leaves your card a dead enchantment that never moves, so the slot is a metagame bet, oversized and free against the right opponent, useless against the wrong one. The timing detail worth noticing is that the opponent controls the transformation. The body materializes on their artifact cast, typically during their own main phase at sorcery speed, so they see the 5/3 before they commit to combat. This is not an ambush; it is a tax that turns their development into your blocker, costing them tempo without costing you a card or mana when it triggers. The whole structure is sideboard logic printed onto the front of a card: a green answer to artifacts that asks almost nothing when it works and costs you a card when it does not.