Heimdall stands guard at Bifrost, the rainbow bridge connecting Asgard, the world of the gods, to Midgard, the world of humans. Ever watchful for any threat, Heimdall has the sharpest eyesight and keenest hearing of all the gods and will blow the resounding horn Gjallarhorn at the first sign of the coming of Ragnarok. Heimdall is said to have foreknowledge of future events. He is born of nine mothers and is the sworn enemy of Loki.