Reservoir Kraken

A 6/6 trample with ward for four mana is a rate that should demand an answer, and the design's whole cleverness is that it hands opponents a way to buy peace instead. The combat trigger turns aggression into a negotiation: an opponent can tap one of their own creatures to shut the Kraken down for the turn, but the cost of that bribe is a 1/1 unblockable Fish that comes to you. It is a symmetrical stalemate machine that only ever tilts one direction. Refuse to pay and the 6/6 tramples in; pay every turn and you accrete an army of evasive tokens that grinds the same opponent out regardless. The tension is real for the defender and nonexistent for the caster, which is a rare and elegant place to land a beater: the card wins whether it swings or sits. The self-tapping clause is what stops it from being an unconditional wall of value (choose to protect the Fish engine and you leave yourself open, choose to attack and you forfeit the Fish that turn), so it rewards reading the board rather than jamming. This is a top-of-curve blue creature built around the psychology of the deal, not the size of the body, and the body is already fine.