Ulthos, the Awaken

Ulthos, the Awaken enters the battlefield tapped.
{t}: Add {r} to your mana pool.
{t}: Put an Eruption counter on Ulthos, the
Awaken.
Whenever Ulthos, the Awaken has five or more Eruption counters on it, remove them and
Ulthos, the Awaken deals 5 damage to any target.