In Norse mythology, the guardian of the Bifrost bridge is Heimdall. He is known for his keen senses and vigilance, tasked with watching over the bridge that connects the realms of gods and humans. Heimdall's ability to hear grass grow and see for miles signifies his role as a protector, alerting the gods of any impending threats. His character embodies themes of watchfulness and duty, highlighting the importance of vigilance in maintaining cosmic order and safeguarding against chaos.