Heimdall is the vigilant guardian of Asgard in Norse mythology, known as the "Whitest of the Gods" with golden teeth (Gullintanni), possessing superhuman sight and hearing, able to see for miles and hear grass grow, guarding the rainbow bridge Bifröst, and wielding the Gjallarhorn to herald Ragnarök, ultimately fighting and dying with Loki. He is a son of Odin and nine mothers, also called Rígr, and rides a golden-maned horse, Gulltoppr.

Key Characteristics:
Guardian of Bifröst: His primary role is to watch over the rainbow bridge connecting Asgard (gods' realm) and Midgard (human realm).
Superhuman Senses: He needs little sleep, sees for hundreds of miles day and night, and hears grass grow or wool sprout.
Possessions: Carries the Gjallarhorn (Resounding Horn) to warn of danger and rides the horse Gulltoppr.
"Whitest of the Gods": A description of his purity, sometimes linked to light, with other names like "God of Light" or "Brightest of Gods".
"Golden Teeth" (Gullintanni): An epithet, possibly connecting him to the sun or sky.
Father of Mankind (as Rígr): In one myth, he fathered the three classes of humanity (thralls, freemen, nobles).
Foreboding Role: He is destined to blow his horn to signal Ragnarök (the end of the world) and will fight and kill Loki in the final battle, but die from Loki's poison.

Other Names & Associations: Rígr (associated with social classes), Hallinskiði (meaning unclear), Vindlér (Wind-Sea/Protector against Wind), He lives in Himinbjörg ("Heaven's Cliffs") at the end of Bifröst. Heimdall embodies vigilance, loyalty, and the boundary between worlds, making him a crucial figure in Norse cosmology and prophecy.