Sorcery, 5R (6)
Uncommon
Jaws of Stone deals X damage divided as you choose among any number of target creatures and/or players, where X is the number of Mountains you control as you cast Jaws of Stone.
When giants find their mountain homes infested, they have a whole range of solutions.
Illus. Zoltan Boros & Gabor Szikszai

5/1/2008: The amount of damage is locked in as you cast Jaws of Stone. It won't change, even if the number of Mountains you control changes.
5/1/2008: If you control no Mountains as you cast Jaws of Stone, the number of targets must be zero.
5/1/2008: If you control any Mountains as you cast Jaws of Stone, the number of targets must be at least one and at most X. You divide the damage among the targets as you cast Jaws of Stone. Each target must be assigned at least 1 damage.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Classic (MTGO)
Legal in Commander
Legal in Modern