HEIMDALL Watchman on the Rainbow Bridge, Bifrost, Heimdall guarded the approach to Asgard, and for this his senses were razor-sharp, his eyes so keen that he could see the wool growing on the backs of sheep, though they were at the other side of the world, and his ears so acute that he could hear grass growing. Heimdall carried a great battlehorn, whose sounding was to signal the final battle, Ragnarok as the giants from Jotunheim swarmed across Bifrost, into Asgard.