Grove of the Burnwillows

Flying Landfall — Whenever a land you control enters, you may create a 1/1 white Bird creature token with flying.

When you cast this spell, reveal the top X cards of your library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield. Then shuffle the rest into your library. This creature enters with X +1/+1 counters on it.

Nonbasic lands are Mountains.

Double strike This creature enters with X +1/+1 counters on it. 1R/G: Put a +1/+1 counter on this creature. Activate only as a sorcery.