Dreamwinder

Most blue creatures of this size buy their way past the early game on evasion or a tempo trigger; this one hard-locks itself to the opponent's manabase instead. The body refuses to swing unless the defending player controls an Island, which against the wrong opponent means it simply never attacks. The fix is bolted onto the same card: spend a blue and feed it an Island, and any land you target turns into an Island for the turn. The intended sequence is self-contained: convert one of your opponent's lands, then send the Serpent in to crack the wall you just installed. What makes the design tense rather than merely clunky is that the unlock costs you land, every activation eats one of your own Islands, so a creature billed as a beater is also quietly a resource sink that shrinks your mana while it tries to get through. The land-type conversion has a second face that the attack clause was never really about: the same activation can strip an opponent's nonbasic of its types or shut off an ability that keys on a specific land, which is where the card's real utility tends to live. As a Serpent built to punish a blue mirror that was happy to leave its Islands on the table, the attack restriction reads as flavor first and function second; the conversion ability is the part worth keeping.