The Great Mountain Giant

If The Great Mountain Giant would be put onto the battlefield by another spell, put it into your hand instead.

Immovable—The Great Mountain Giant can't be put into your hand or library from the battlefield.

When The Great Mountain Giant dies, return it to the battlefield transformed under its owner's control.

{x}{r}, {t}: put X +1/+1 counters on The Great Mountain Giant. Activate this ablility only if you control X mountain cards.