Ixtal, Luxuriant Jungle

At the beginning of each player's upkeep, that player creates a colorless Egg artifact token
with "Tap: Add one mana of any color" and "Sacrifice this artifact: Reveal cards from the
top of your library until you reveal a creature
card with mana value equal to or less than the
number of lands you control. Put that card
onto the battlefield and the rest on the bottom
of your library in a random order."