Bladecoil Serpent

When Bladecoil Serpent enters the battlefield, for each UU spent to cast it, draw a card. When Bladecoil Serpent enters the battlefield, for each BB spent to cast it, each opponent discards a card. When Bladecoil Serpent enters the battlefield, for each RR spent to cast it, it gets +1/+0 and gains trample and haste until end of turn.