The Serpent, the God of Fear, is an ancient creature who was locked away By Odin himself eons ago and now is free thanks to the efforts of Sin, the Red Skull's daughter. He is the primary antagonist of the Marvel storyline "Fear Itself".
Claiming to be the true all father of Asgard, he wishes to see Odin destroyed. As he walks out of his prison, he summons 7 mystical hammers to choose anyone to become The Worthy. Sensing his return, Odin forces all Asgardians to leave for Asgard space, despite the protests of Thor, who is forced to leave as well. It is revealed that The Serpent is the one that Thor is prophesied to die in battle instead of Loki's son, the Midgard Serpent.