Heimdall

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

- Heimdall

Heimdall is the all-seeing and all-knowing Asgardian warrior-god and the guardian of the rainbow bridge, Bifrost, watching for any attacks on Asgard.

Thor
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 jotuns when they stole 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. Although Heimdall agreed to let them pass and accepted their request that he keep their movements secret, his loyalty to Odin was stronger and he immediately reported their departure. Odin's reaction was swift and had Heimdall opening the Bifrost twice more in quick succession to allow Odin to retrieve his people.

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 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, but Loki simply froze him in a block of ice before the blow could strike.

Heimdall was still frozen when Loki brought several jotuns 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 galvanised by the calls of Thor who was still trapped on Earth. Smashing free, he quickly cut down two jotuns 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.

He 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 still looks for him.

Thor: The Dark World Prelude
The nine realms sensed a change due to the destruction of the Bifrost and Heimdall noticed. He told Thor and Odin. As Thor was about to leave, Heimdall asked him if he wanted to know what was happening with Jane on Earth, Thor said he would like to, but not at that moment

One year later, Heimdall informed Odin and Thor that Loki was on Earth. Sif inquired about Thor's journey to Earth, querying whether he had survived to which Heimdall replied "Thor lives".

After Loki was defeated and returned to Asgard, Heimdall and Thor used the Tesseract to re-build the Bifrost.

Thor: The Dark World
"We face an enemy known only to a few... Known only to ONE."

- Heimdall and Thor Odinson

Heimdall is the sentinel of Asgard with the ability to see and hear events galaxies away. He stands at his post in Asgard’s Observatory, watching over the cosmos and protecting Asgard from any and all intruders. As one of Odin’s most trusted warriors, Heimdall is beyond reproach… but now Asgard faces an enemy that even Heimdall cannot see.

"Who You Really Are"
Lady Sif calls upon Heimdall to open the Bifrost Bridge.

Avengers: Age of Ultron
"The son of Odin, you must wake up! You must save us!"

- Heimdall

To be added

Character traits
Heimdall is a strong and loyal warrior, with a high sense of honor. Although being extremely powerful, even for an Asgardian, he serves loyally Odin, having swore to be faithful to his king. He is a very quiet person, often with his attention turned towards other worlds, but to those who mean no harm to the people of Asgard he can be somewhat friendly, and has even greeted Jane Foster, a human, to Asgard with quick wit. He also not above taking time off and sharing a meal with his fellow citizens when his services are not needed, such as when Odin closed off the Bifrost after the death of Queen Frigga.

Power and Abilities
As all Asgardians, he possesses superhuman physical attributes, such as strength, reflexes, stamina, speed, agility, durability. However, he is generally stronger and more durable than all but a few Asgardians, such as Odin and Thor, so much so that Loki was curious to know the reason why Odin did not fear the powerful gatekeeper. He's an extremely skillful swordman, wielding an enchanted uru sword in battle.

Heimdall possesses extraordinarily acute superhuman senses, most notably his vision and hearing, bordering on the extrasensory. His senses are said to be so acute that he could hear sap running through trees, and "the tiniest plant growing in the heart of the hidden hills", and see and hear anything occurring in Asgard or on Earth. Heimdall can also "look across time, as well as space". Heimdall has been said to be capable of detecting the fluttering of a butterfly's wings "a thousand worlds away". His sensorial powers can be deceived, as Loki proved.

Relationships

 * Odin - King.
 * Frigga - Queen.
 * Loki - Former ally and king, enemy.
 * Thor - Ally.
 * Warriors Three - Allies.
 * Sif - Ally.
 * Laufey and Frost Giants - Enemies.
 * Malekith and Dark Elves - Enemies.

Appearances/Actors

 * Marvel Cinematic Universe (3 films)
 * Thor (First appearance) - Idris Elba
 * Thor: The Dark World - Idris Elba
 * Avengers: Age of Ultron - Idris Elba
 * Thor: Ragnarok - Idris Elba
 * Marvel Cinematic Universe (1 TV series)
 * Agents of S.H.I.E.L.D.
 * "Who You Really Are" (Mentioned only)
 * Marvel Cinematic Universe (1 comic)
 * Thor: The Dark World Prelude

Behind the scenes

 * The Council of Conservative Citizens planned to boycott the movie since a black actor was cast to portray a Nordic god. Idris Elba commented the criticism as "ridiculous".

Trivia

 * In the comics, Heimdall and Sif are siblings. This was not explored in the film.
 * In Norse mythology, Heimdall guarded the Bifrost, which the Vikings believed a rainbow was. Mythology also states that he was born in the ocean from the Nine Mothers and blew the horn Gjallarhorn to signal incoming invasions on Valhalla. Heimdall was predicted to kill and be killed by Loki during the doomsday scenario of Ragnarok.