Thanatos is an enemy from Final Fantasy Mystic Quest. It resembles the boss enemy Dullahan. Unlike its counterpart it has many elemental weaknesses and can easily be defeated. He can also restore his lost HP with Cure.
The creature has three phases. First he rides a headless galloping horse. The second phase has the horse slump to its knees. The third phase has him rush at the party with sword drawn and his helmet's red eyes glowing.
Thanatos, or Thanatus, is the dæmon personification of Death in Greek mythology.