Lair Lurker

Mountainwalk
When Lair Lurker enters the battlefield, destroy target creature with flying. If that creature is a Dragon, put X +1/+1 counters on Lair Lurker, where X is equal to the destroyed creature's
power.
"Many dangers inhabit a dragon's lair, some worse than the dragon itself."
- Dydun, Shivan Lair Delver