Rat Lab

When Rat Lab enters the battlefield, create a 1/1 black Rat creature token with deathtouch.
{1}{b}, Sacrifice a rat: Reveal cards from the top of your library until you reveal a rat. Put that card into your hand. Put the rest on the bottom of your library in a random order.
{2}{b}{b}: Each opponent loses X life, where X is the number of rats you control.