Cocoon

Several upkeeps of locked-down dormancy in exchange for a permanent +1/+1 and flying: the Aura is a metamorphosis simulator rendered in counters, and the design discipline that makes it cohere is the self-resolving timer. Most early auras either buffed a creature immediately or punished it forever; this one does both in sequence, taking the host offline the moment it lands (tapped, with three pupa counters) and then returning it transformed once the counters run out. The sequencing is slower than it looks: a counter comes off each upkeep, so the creature sits idle for several of your turns before the upkeep arrives where you cannot remove one and the chrysalis breaks. The pupa counters do double duty as both the lockout mechanism and the countdown, which is unusually tidy for the era. The cost structure is honest about what it asks: one green mana and a creature you were planning to attack with, frozen for the better part of a game cycle, in exchange for an evolution payoff that arrives on a schedule the opponent can read off the board. That legibility is the catch. A removal spell at any point during the chrysalis phase eats the host and the investment together, and the enchanted creature cannot even chump-block while it waits. The flavor argument is what survives: a caterpillar becomes a butterfly, and Magic's counter vocabulary in 1994 was flexible enough to literalize the metaphor without inventing a new keyword.