Whats Behind the Wall?

At the beginning of each opponents upkeep, that player reveals a card at random from their hand.
If its a creature or enchantment card, they lose
life equal to its mana value. If they dont reveal a creature or enchantment card this way, they
discard that card and lose 3 life.
Squelching, its horrid stench and putrid slime leaked
and smushed through the weak brick walls, its
features were human, yet so far from it.