Gruul Scrapper

Cast it for and you get a 3/2 that does nothing on arrival; route a red pip through the generic portion of that same cost and it charges in with haste. The trick is that the printed cost names no red at all: the trigger checks the actual mana you tapped, not the symbols on the card, asking whether a red mana paid for any of those three generic slots. That distinction is the whole design. It rewards committing to a second color rather than splashing a lone pip, while never punishing the green-only mode, because a card that demanded the red would have been a worse green creature and a card that gave nothing for the red would not have taught the lesson. The reward is calibrated to the body: haste on a 3/2 matters enough to register (the difference between trading and landing a hit) but stays small enough that the conditional reads as a bonus, not a tax. The Berserker line is the flavor that explains the math: a creature built to attack the turn it lands, with a trigger that exists to let it. A modest piece, but a precise one, and an early, legible instance of the conditional-payment template, a small machine for showing what a two-color mana base buys you beyond fixing.