Oran-Rief, the Vastwood

This land enters tapped. Whenever a Mountain you control enters, if you control at least five other Mountains, you may have this land deal 3 damage to any target. T: Add R.

Destroy all creatures.

Trample Landfall — Whenever a land you control enters, create a 4/4 green Beast creature token.

This spell can't be countered. Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)