Aegrem, the Bio-Elementalist

When a land enters the battlefield under your control, you gain three life and draw a card,
then you may put a land card from your hand
onto the battlefield.
{g/u}{g/u}, {t}: Reveal any number of lands
from your hand, you may return that amount
of lands from the battlefield to your hand.
Aegrem's power and toughness are each equal
to the amount of lands you control.