Grabby Giant // That's Mine

Cast That's Mine first for a Treasure, and the giant that later ships out of exile arrives with the first artifact its engine wants to eat: the Adventure front-loads a mana rock, and the creature side is a sacrifice-for-cards machine that will happily consume it. On the battlefield the 4/3 with reach is a serviceable blocker, but the activated ability is where it earns its keep, turning artifacts and lands into fresh cards three mana at a time. Red almost never gets to draw its way out of a stalled board without leaning on rummaging or impulse effects; this instead converts spent permanents into raw cards, which is a rare thing for the color to do at all. The cost is the sacrifice itself: each draw eats a permanent you have to be willing to part with, so the engine only runs as long as you keep feeding it lands you no longer need or artifacts you can spare. That constraint is what keeps a repeatable draw ability from spiraling. The two-part structure carries the real design load, splitting a burst of early ramp and a slow late-game grinder across two casts so the same card can be a cheap Treasure when you are behind and a mana sink when the game grinds long.