Loki

Jormungundr, the Midgard serpent, juge and dangerous, will writhe in its fury, closer and closer to the land. The venom from its fangs will spill into the water, poisoning all the sea life. It will splatter its black poison into the air in a fine spray, killing all the seabirds that breathe it.
There will be no more life in the oceans, where the Midgard serpent writhes. The rotted corpses of fish and of whales, of seals and sea monsters, will wash in the waves.