Bone Spine Hellkite

Flying, Scar (This creature deals damage to creatures
without Scar in the form of -1/-1 counters. This
creature cannot have -1/-1 counters placed on it.)
When this creature dies, it deals 4 damage to any
target.
When a Mountain comes into play, you may
transform this card to Widening Hellhole
Crevasse.
Fully open, the behemoths of Hell emerge."