Veil of Birds

A creature you deploy as a non-creature, then hand the moment of animation to the player across the table. It sits on the battlefield as a static enchantment, with nothing to maintain and nothing for creature-targeted removal to grab, until an opponent casts a spell and a triggered ability puts itself on the stack above that spell, resolving first and turning the permanent into a 1/1 Bird with flying before the spell that woke it ever finishes. The inversion is the whole conceit: the controller has no say in when the Bird arrives, because the trigger keys off the opponent's spellcasting, not their own. That also means the timing is not bound to a turn. An opponent who holds an instant or a flash creature can animate the Bird during the controller's turn just as easily as on their own. The conditional self-check ("if this permanent is an enchantment") keeps the transformation a one-time event, so a second spell on the stack finds nothing left to convert. It belongs to a strain of early-era design fascinated with the seam between card types, permanents that read as one thing until a condition flips them into another. The strategic payoff stays modest: a 1/1 flier whose arrival you cannot schedule can chump an attacker, peck for an evasive point, or feed a sacrifice outlet, but rarely earns its card. The curiosity outlasts the rate, animation permanently outsourced to the opponent.