Heimdall

"Never before has an intruder slipped past me. I want to know how."

- Heimdall

Heimdall is the all-seeing and hearing Asgardian and guard of the Bifrost Bridge. He can see and hear nearly everything that happens in the Nine Realms. He is the current owner of the Tesseract.

Thor's Coronation
Heimdall is an Asgardian blessed with sensory capabilities far beyond those of other Asgardians, and these senses have been put to use placing Heimdall in the role of gatekeeper to Asgard at his observatory on the Bifrost Bridge. Despite his phenomenal ability however, Heimdall was unable to perceive an intrusion by several Frost Giants when they broke into the vaults of Odin. This same intrusion also sparked the ire of Odin's son Thor, who came to Heimdall, with several of his friends, seeking access to Jotunheim. Heimdall agreed to let them pass and accepted their request that he keep their movements secret.

Loki Takes the Throne
Later, with Thor banished and Odin fallen into his Odinsleep, Loki placed himself on the throne as regent and demanded Heimdall's loyalty. Although he grudgingly accepted, Heimdall opted to only observe a literal interpretation of his vow to Loki and did not interfere when Sif and the Warriors Three used the Bifrost Bridge to reach Thor. Enraged, Loki dismissed Heimdall as a subject, thus releasing the protector of the Bifrost from his vow. Heimdall responded with an immediate attack with Hofund, but Loki simply froze him in a block of ice with the Casket of Ancient Winters before the blow could strike.

Heimdall was still frozen when Loki brought several Frost Giants, including Laufey, through the Bifrost. Locked in his icy prison, he was helpless to prevent Loki leading one of them into the city, but he was soon galvanized by the calls of Thor who was still trapped on Earth. Smashing free, he quickly cut down two Frost Giants who had been left to guard, and opened the Bifrost for Thor and his friends. Severely weakened, Heimdall could assist the adventurers no further and had to be carried from his observatory.

After he left, Thor defeated Loki in a duel, at the cost of the Bifrost Bridge. The destruction of the bridge created a portal that sent Loki to an unknown area in space. Heimdall returned following the destruction of the observatory and when Thor asked if passage to Earth was lost, he shows him the Bifrost regenerating and replied, "No. There is still hope." When Thor asked Heimdall if he could see Jane Foster, Heimdall chuckled and told him that she was still looking for him.

War Between Realms
"With the death of Laufey and Loki's attack on their world, the Frost Giants are a broken people... and yet they sense something has happened. The Troll Lords know it as well. For many millennia, they have coveted the Dwarven forges. Once they realize that Asgard cannot come to king Eitri's defense, they will strike. Despite their primitive nature, the Badoon feel our absence. Several of their clans have fallen into civil war. Their savagery and bloodlust will eventually spread from planet to planet unchanged. And the Marauders amass near Vanaheim. Thor's destruction of the Bifrost continues to shift the balance of power across the Nine Realms... and into the worlds beyond Yggdrasil."

- Heimdall With there being no way for the Asgardians to go to other Realms to help protect them, the other Realms of the universe fell into chaos. To keep the Asgardian leaders updated, Heimdall summoned Odin and Thor and warned them about the attacks. Thor, realising that his friend Hogun would worry about his people in Vanaheim, chose to tell him about it. Thor asked Hogun to tell him if anything changes in the realms, especially Vanaheim.

Loki's Survival
Around a year after the Duel at the Bifrost Bridge, Frigga discovered Loki was in Chitauri Space. There, Loki was being trained by Thanos to rule Midgard. Soon Loki went to Midgard and started the War for Earth. With the Bifrost destroyed, Odin was forced to use dark energy to send Thor after Loki. With the help of the Avengers, Thor was able to arrest Loki and take him back to Asgard along with the Tesseract following the Battle of New York. Thor entrusted the Tesseract to Heimdall upon his return to Asgard. The all-seeing Asgardian then used it to repair the Bifrost Bridge.

Return of the Dark Elves
As Heimdall and Thor discussed Jane Foster, Heimdall lost track of her, causing Thor to travel to London to check on her. When Thor and Foster came across the Bifrost Bridge, Heimdall greeted them. Later, he witnessed as Fandral, Volstagg and the Einherjar returned from fighting the Marauders with their captives. Among the Marauders was Algrim.

Simultaneously, as Algrim was conducting a prison break of the Asgardian Dungeons, Heimdall observed something strange flying pass him. He left his post on the Bifrost Bridge and chased it down. It was the lead Dark Elf Harrow trying to invisibly pass him. After destroying the ship, Heimdall used Hofund to activate the shield around Asgard.

After the funeral of Frigga, Odin decreed that the Bifrost be shut down. Not needing to guard his post, Heimdall went to console Thor. As they spoke, Thor asked Heimdall to side with him as he hid Jane Foster, who was carrying the Aether. When Odin was told by Tyr that the mortal woman was missing, Odin looked disappointedly at Heimdall.

Appearance and Traits
Heimdall is a strong and loyal warrior, with a high sense of honor. Although being extremely powerful, even for an Asgardian, he loyally serves Odin, having swore an oath of faith to his king. He was loyal enough to confess his disobedience (although he called it treachery) to Odin and surrender.

Equipment and Skills
As all Asgardians, he possesses superhuman physical attributes, such as strength, speed, stamina and reflexes, and he's an extremely skillful swordman. He also has the power of nigh-omniscience, and his sight can extend itself to all Worlds, but his sensorial powers can be deceived, as Loki proved to trick him.
 * Hofund
 * Armor
 * First Set: Heimdall’s original armor was a gold metal chest plate that extended into shoulder guards over simple brown clothing. He also had a golden horned helmet. He wore black pants and gold boots and arm-bracers.
 * Second Set: Heimdall’s second armor was far more ornate with an illustration of Yggdrasil on his chest plate. His sleeves are gold and brown leather. He wore a gold and brown skirt over brown pants and detailed golden boots. Heimdall still wears a helmet that is the same shape as the first one but with patterns etched onto it.

Allies

 * Thor
 * Sif
 * Warriors Three
 * Hogun
 * Fandral
 * Volstagg
 * Odin - King
 * Frigga † - Queen
 * Jane Foster

Enemies

 * Frost Giants
 * Laufey †
 * Loki - Former Ally and King turned Enemy
 * Dark Elves

Video Game Only

 * Fire Demons - Enemies

Trivia

 * In the comics, Heimdall and Sif are brother and sister. Although this relationship has not been explored in the movies, concept art exists portraying Sif as black, confirming that this relationship was originally propped for Thor.
 * In, Heimdall guarded the Bifrost, which the Vikings believed rainbows came from. Heimdall was predicted to kill and be killed by Loki during the doomsday scenario of Ragnarök.

Behind the Scenes

 * Heimdall is the only other Asgardian besides Thor to appear in films outside of the Thor franchise. Loki does not count, as he is a Frost Giant.