Ilkayan Nightborn

Nightmare -{2}{g} (This creature enters the battlefield with a dream counter on it. You may pay its nightmare cost at any time to remove a dream counter from it. Creatures with dream counters on them are enchantments and lose all other card types.)
Once pacifistic Ilkayans were driven insane as their connection to the Dream twisted their bodies and minds to Nightmare. The corruption turned them to violence against those who had not embraced the Truth as they had.