The Goose Mother

An X-spell hydra that pays you twice for the same mana investment, which is the whole design trick. The X you pour in does double duty: it sets the body's size through +1/+1 counters, and it bankrolls a card-advantage engine by stocking Food at a rate of half X, rounded up. That rounding is the quiet generosity of the line; even a small X leaves you with fodder for the attack trigger, and a large X turns the board into a pantry. The Simic color pair has chased the "ramp your mana into something that refunds itself" template for years, and this folds three jobs (a flyer, a scalable threat, a repeatable draw outlet) into a two-color legend at a curve point you choose. The sacrifice-on-attack clause is the part that makes it a commander rather than just a fat green creature: it asks you to keep swinging to cash the Food in, tying the card-draw to combat tempo instead of letting it sit back. Build around the Food half and the body becomes incidental; build around the counters and the cards are gravy. Either way the engine wants the same thing, which is more mana to feed the X, and the Food layer means the resource you spent does not fully evaporate once the creature resolves.