Iridescent Tiger

Cast a red creature, get back one of every color: that inversion is the whole point. This is fixing dressed as a five-mana beater, a way to reach white, blue, black, and green costs from a mono-red anchor, and the rebate is a full rainbow that refunds the outlay and threads straight into whatever five-color payload the same turn wanted. The conditional on the trigger is doing real gatekeeping work: the payoff only fires "if you cast it," which walls off the reanimation and blink shortcuts that would otherwise put the body onto the battlefield for free and still collect the mana. Note the exact scope of that fence, though. It stops effects that drop the Cat straight onto the board, but it does not stop free-cast shortcuts: cascade, discover, and Omniscience all cast the card, so the trigger still fires when you arrive there without paying. The restriction bites reanimators, not spell-cheaters. Because the mana appears on the enter trigger rather than as an activated ability, it lands at whatever speed you paid for the creature; there is no repeatability, no engine, just a single flood the moment the Cat resolves. The 3/4 body is almost incidental, a token of board presence to justify the ramp. What the card really wants is a hand full of expensive spells and a turn where five colors of mana unlock two plays at once.