The Shapeshifter 1

As long as the top card of your graveyard is a creature card, this creature has the full text of that card and has the text ": Discard a card." (This creature has that card's name, mana cost, color, types, abilities, power, and toughness.) : Discard a card.

When Phage enters, if you didn't cast it from your hand, you lose the game. Whenever Phage deals combat damage to a creature, destroy that creature. It can't be regenerated. Whenever Phage deals combat damage to a player, that player loses the game.