Argothian Wurm

A 6/6 trampler for four mana was a genuinely aggressive rate in an early era of design, the size of body that usually demanded a steeper cost or a punishing keyword. The drawback here is unusually elegant: the enters trigger lets any player, including its own controller, sacrifice a land to bounce the Wurm to the top of its owner's library. That openness is the whole engine. An opponent can pitch a land of their choice to buy a turn against a 6/6, paying with their own development to do it; or, if no one is willing to spend a land, the Wurm simply stays and tramples. And because the controller is also "any player," the card can be deliberately recurred: sacrifice a land yourself, draw it next turn, recast it, and force the same decision again. Each cast becomes a small negotiation over resources, asking whether stopping the body for one turn is worth a land off someone's mana base. It plays best in shells that can replace lands quickly enough to make repeated sacrifices cheap for you and expensive for them, or alongside effects that keep the Wurm on the battlefield once it lands. The trigger is optional all around, so a player with nothing to spare just eats six power. The stat line writes a check; the surrounding deck has to figure out how to cash it, and that tension outlives the raw numbers.