Poliwhirl

You may sacrifice a creature named Poliwag
rather than pay this spells mana cost.
Protection from monocolored-blue.
{t}: Tap target creature. It doesn't untap during
it's controller's next untap step.
{u}, {t}: Poliwhirl deals damage equal to its
toughness to target attacking or blocking creature.
{1}: Poliwhirl gets +2/-2 until end of turn.