Milk Shortage

At the beginning of your upkeep, if a creature
you controlled left the battlefield during your
last turn, you gain 2 life and analyse 2. (Look at
the top two cards of your library. Put up to one of those
cards into your graveyard and the rest on top of your
library in any order.)
At the beginning of your end step, if you didn't
gain life this turn, sacrifice a creature.