Mardu Outrider

The trade is stated plainly: a 5/5 for three mana asks you to throw away a card before it ever hits the table. That rate is aggressive by any measure, and the discard is the whole balancing mechanism. A body this large this early would warp any environment built around it, so the design taxes it not with a scaling cost or a downside trigger but with immediate card disadvantage, spent at cast, no way to recoup. It is one of the cleanest teaching examples of the discard-as-cost lever, a design tool that lets a creature's stats run far ahead of its mana value in exchange for a one-time hit to resource parity. The card also flatters graveyard strategies almost by accident: if the thing you pitch is a card you wanted in the yard anyway (a reanimation target, a delve fuel, a flashback spell), the additional cost stops being a cost at all. Built as a straightforward beater for a black player learning why big creatures usually cost more, it quietly doubles as a demonstration of when a strict downside becomes an upside, which is the more interesting lesson.