Urborg Panther

Mirage built a handful of creatures as literal recipe cards, and this is one piece of a three-ingredient combine: collect this Cat, a creature named Feral Shadow, and a creature named Breathstealer, sacrifice all three, and Spirit of the Night arrives directly onto the battlefield, a 6/5 flier with first strike, trample, and swampwalk that would otherwise cost a fortune to hardcast. The design is a named-component assembly puzzle that predates most modern tutor-and-stitch templating: you do not search for the parts, you line them up across your deck and pay them all to summon the payoff. It is a steep tax (three card slots committed to skip the mana on a fourth), and that commitment is exactly why the combo never traveled far past flavor. The other half of the card is the clause that actually saw a hand, and it is strictly an aggressor's tool: a black mana plus the body destroys a creature blocking it, so the Panther has to be the attacker, and the line only comes online once a defender has declared the block. Punch through a wall by killing the thing in its way, then sacrifice for the kill rather than wait on damage. That everyday function kept the card from being a pure museum exhibit for its recipe, but the Spirit of the Night summon is the reason it is remembered, an artifact of a design philosophy that built individual creatures as ingredients in a named dish rather than as flexible, reusable parts.