Lair of the Eternal Serpent

Lair of the Eternal Serpent enters the battlefield
tapped unless you control another Legendary
permanent or if you control a snake creature.
{t} : Add {b} or {g}.
{2}{b}{g}{t}: The next creature you cast costs
{10} less.
{b}{g}{t}: Choose a card type. Reveal the top five
cards of your library. You may put a card of the
chosen type from among them into your hand.
Put the rest into your graveyard.