The One Ring

Equip {10}
Indestructible, hexproof
Equipped creature gets +5/+5
At the beginning of each upkeep, put a Wraith
counter on equipped creature.
If equipped creature has 10 or more Wraith
counters on it, it becomes a Wraith in addition to
its other creature types and it gets +X/+X
where X is the amount of Wraith counters on it.
Exile this card if an opponent controls 15
mountains.