Nightmare of Skydeep

Defender, deathtouch, reach
Nightmare of Skydeep enters the battlefield tapped.
When Nightmare of Skydeep enters the battlefield, you may exile nine cards from your graveyard. If you do, Nightmare of Skydeep gets +9/+0 and loses defender.
"Sailors say it's harmless, yet those who go out to hunt it never return. I just keep my distance."
-Captain Jarkleb of the Sea Drake