Fallow Wurm
The bill comes due the instant it resolves: pitch a land from hand or watch the wurm sacrifice itself before it has swung once. The discount is paid as a one-time discard rather than a recurring upkeep tax or a smaller body, and that structure turns the card into a tempo gamble rather than a value engine. You trade a card and a point of land development for an oversized body that hits harder than its mana value should allow, and you make that trade up front, before the creature has done a thing. The friction is deliberate. Green's reward for the discount is paid in resources you would rather keep, and the sacrifice clause closes the obvious loophole: you cannot dodge the cost by simply holding no land, because an empty hand kills it on the spot. It belongs to a school of cost-pushed creatures from Magic's first years, before the modern grammar of saddling fatties with sorcery-speed restrictions or kicker had settled, when "discard a land or lose it" was a reasonable lever for jamming a fat body onto an early battlefield. The math reads worse the longer a game runs, which is exactly the point: this is a creature built to be cast while cards are still cheap and lands are still plentiful, and a dead draw once a hand has thinned out.
