Aquaman, King of The Sea

Vigilance, ward {3}

Whenever you cast a Kraken, Leviathan, Octopus,
or Serpent spell from your hand, look at the top X cards of your library, where X is that spell’s mana value. You may cast a spell with mana value less
than X from among them without paying its mana cost. Put the rest on the bottom of your library in a random order.