Wild Cantor

A 1/1 body that exists to be thrown away, and that is the entire point. The hybrid casting cost lets it slot into either a red or green deck at the same price, then converts itself into a single mana of any color the instant you need it. That makes it a Druid-shaped Lotus Petal with a pulse: a one-time ritual that fixes a splash, smooths a combo turn, or pays for a color you have no permanent source of, all while leaving a creature on the board until you cash it in. The sacrifice clause is what keeps the rate fair; you are not getting a permanent mana source, you are getting one extra mana when you spend the card. For the kind of deck that needs to hit a precise color on a precise turn, that one mana of any color is worth more than a vanilla one-drop ever would be. The death is baked into the mana ability rather than left to combat or removal, which means it triggers death-payoffs like Blood Artist on its own terms, the moment you decide to spend it. Just note that the sacrifice is the cost of its own activation, not free fodder for an outlet: you can feed an Ashnod's Altar, or you can take the rainbow mana, but a single Wild Cantor cannot do both. A small piece, but a deliberate one: a creature that doubles as ritual acceleration and rainbow fixing, asking only that you choose the moment to let it die.