Plundering Pirate
The template for aggressive red at three mana: a body that trades up in combat and an artifact left behind when it dies, so the tempo loss of removing it comes attached to a mana rock the removal spell can't touch. The Treasure is what turns this from a plain 3/2 into a genuine two-for-one. It smooths a color splash, powers out something bigger a turn early, or feeds an artifact-sacrifice engine, and because it arrives the moment the Pirate does, the value is banked immediately rather than dependent on the creature surviving. That front-loading is the whole logic of the card: the moment it resolves, you have already gotten a fraction of your mana back and a body that still has to be answered. Pirate typing ties it to the raiding-and-plunder identity where Treasure is thematic currency, but the design reads more broadly as red splicing a scrap of ramp and fixing onto a curve-filling attacker, a job red usually pays for with sacrifice or self-damage. Here the cost is simply the modest 3/2 frame, which is fine when the artifact is doing half the work.
