Loki

"Treacherous Odin!" called the wolf. "if you had not lied to me, I would have been a friend to the gods. But your fear has betrayed you. I will kill you, Father of the Gods. I will wait until the end of all things, and I will eat the sun and I will eat the moon. But I will take the most pleasure in killing you."

[...]

Then, when the few remaining people are living like animals, the sun in the sky will vanish, as if eaten by a wolf, and the moon will be taken from us too, and no one will be able to see the stars any longer.