Frightshroud Courier

Tapping a creature to pump another is old technology; the wrinkle here is binding the buff's lifespan to the tapper's posture. The clause that lets the Courier skip its untap step is the whole engine: the +2/+2 and fear cling to a single Zombie only while this body stays sideways, turning the boost into a held investment you keep paying for in board presence. Park it down, leave it parked, and one ground-bound Zombie becomes a threat that slides past anything that isn't a black or artifact creature. The cost asks for the tap plus three mana to make the pump live, which is why the Courier earns its keep the turn after it lands rather than the turn it arrives. Fear was the period-correct evasion keyword for black aggression, and bolting it onto a chosen Zombie while sizing that body up by two let a tribal deck convert a clogged board into a single unblockable line of damage, lethal whenever the opponent has no black or artifact blockers to interpose. It belongs to a cycle of Couriers that ran the same trick across different creature types; this one's job is squeezing a Zombie horde through a stalled ground and then holding it open, the buff persisting exactly as long as you're willing to leave the lord lying down.