Mjölnir

"Whosoever holds this hammer, if he be worthy, shall possess the power of Thor"

- Odin enchanting Mjölnir

Mjölnir was the primary weapon of Thor, the Asgardian God of Thunder. It was an enchanted hammer of tremendous power that grants Thor the ability to fly and summon lightning against foes. As of Thor: Ragnarok, Mjölnir was destroyed by Hela.

Iron Man 2
S.H.I.E.L.D. Agent Phil Coulson drove to a remote impact crater in the New Mexico desert. Over a phone, he informed Nick Fury that they had found "it". Mjölnir was in the middle of the crater.

Thor
Mjölnir is said by the Asgardian king Odin to have been forged in the heart of a dying star and having "no equal as a weapon to destroy or as a tool to build". In Thor's childhood it is seen in Odin's Trophy Room, and in maturity he uses it as his primary weapon.

When Thor disobeys his father's orders and attacks Jotunheim, Mjölnir proves to be useful against the towering Frost Giants, and gives Thor enough power to have slain many of them.

When Odin intervenes, anyway, he chooses to banish his son to Earth, so that he can learn some humility, and casts a spell on Mjölnir, declaring that it won't come back in Thor's hands until he proves to be worthy of it. Sent to Earth along with Thor, Mjölnir lands in New Mexico, where is found inside a crater by some people living nearby. The citizens starts a contest, trying to lift it, with no results: a man tries to move it using his pickup, thus breaking the car. Later, Phil Coulson finds the hammer too, and builds a S.H.I.E.L.D. research center around it.

When Thor arrives to claim his weapon, he cannot lift it either, since he has still to become a humble and noble man, instead of the proud and belligerent warrior he is. Loki then tries to lift it too, hidden from the S.H.I.E.L.D.'s agents' sight, but obviously fails. When The Destroyer attacks Earth and Thor sacrifices himself to stop it, Odin's spell is broken and Mjölnir flies to his original wielder. With Mjölnir in his hand, Thor easily defeats the Destroyer and comes back to Asgard, where the last battle with his brother awaits. Using the power of Mjölnir, Thor destroys Bifrost Bridge, thus preventing Loki to destroy Jotunheim.

The Avengers
Thor uses Mjölnir against Captain America and Iron Man and it proves unable to break Captain America's vibranium shield. When the Hulk rampages through the helicarrier, Thor seeks to defeat him. During this fight, the Hulk attempts to lift Mjölnir but is unworthy, therefore making Mjölnir one of the only objects the Hulk cannot lift. Thor uses Mjölnir to great effect during the Chitauri invasion.

Agents of S.H.I.E.L.D.
In the episode "0-8-4", Coulson states that Mjölnir was classified as an 0-8-4.

Thor: The Dark World
Thor also used Mjölnir against the Marauders during the War of the Realms, notably destroying a Kronan with one hit, as well as the Dark Elves when they invaded Asgard. Mjölnir was also used to throw lightning at Malekith, burning the right side of his face.

When dealing with the Aether, Mjölnir's lightning managed to shatter it into shards, only for it to reform later Mjölnir was also no match against the Kursed Algrim who simply deflected it when Thor summoned it to strike him. Mjölnir, however worked greatly against Malekith on Earth, with Thor being able to deflect many of his Aether powers. The constant shifting of the fighting between worlds caused Thor and the hammer to become separated, but at the battle's apex, as Malekith unleashed the Aether to complete his plan, Thor was able to summon Mjölnir back to his hand and use it to bury the last of Erik Selvig's gravitational devices into Malekith's chest, allowing Jane Foster to transport the Dark Elf warlord to his death on Svartalfheim.

Thinking he was talking to his father though it was Loki in disguise, Thor offered Mjölnir back to "Odin" who refused it.

Avengers: Age of Ultron
Mjölnir was used by Thor in conjunction with Captain America's shield during their raid on Wolfgang von Strucker's HYDRA base in Sokovia, with Captain America holding the shield up and Thor hitting the shield with the hammer, causing a shockwave that incapacitated their enemies.

Following the battle, the Avengers organized a party at the Avengers Tower to celebrate the recovery of Loki's Scepter and the defeat of Wolfgang von Strucker. Some of the Avengers played a game to see if anyone could lift Mjölnir. Only Steve Rogers managed to move the hammer slightly, which slightly discomforted Thor.

Running at superspeed, Pietro Maximoff saw Mjölnir fly past him as Thor threw it during the Battle at the Salvage Yard. Planning to use it against the Avengers, Quicksilver grabbed the flying hammer; it dragged him across the facility until he released it. Captain America was able to use that opportunity to knock out the dazed and confused opponent.

Acting on a vision he had received, Thor used Mjölnir to recharge the cradle containing Ultron's incomplete biological body, resulting in the birth of the Vision. A few moments later, as the Avengers were debating whether they could trust him, the Vision easily lifted Mjölnir and casually handed it to Thor. Since the hammer had judged him worthy, Thor accepted the android as an ally and, later, advised he be allowed to continue to be entrusted with the Mind Stone.

Mjölnir was once again used in conjunction with Captain America's Shield to create a combination attack that destroyed many Ultron Sentries as the Battle of Sokovia waged. Captain America would throw his shield and allow Thor to hit it with Mjölnir, causing the shield to fly faster as a projectile weapon.

Vision's ability to use the hammer was utilized during the Battle of Sokovia, not expecting anyone besides Thor to use it. Vision commented that Mjölnir was "terribly well-balanced", which Thor said was necessary so that its wielder did not lose momentum on forward swings.

Thor: Ragnarok
Mjölnir was used by Thor when he was imprisoned in Muspelheim. He summoned his hammer to get free of his shackles and then fought Surtur's army of Fire Demons with it. Upon returning to Asgard, after learning from Surtur that Odin was no longer there, Thor used Mjölnir to threaten the "Odin" impostor to reveal himself, and as he suspected he was revealed to be Loki. The two brothers went to Earth to find their father, so in order to hide it from the public, Mjölnir transformed into an umbrella.

Thor was aided by Stephen Strange to find Odin. After the latter located him in Norway, Thor summoned Mjölnir to him, breaking many artifacts of the New York Sanctum in the process. In Norway, before his death, Odin revealed to his sons that they had a sister named Hela who would try to rule Asgard by force after his death. When Hela arrived at their location, Thor threw Mjölnir at her, but she managed to block the attack and hold the hammer with her bare hand. Much to Thor's surprise, Hela destroyed Mjölnir without effort

Capabilities
Mjölnir was forged in the heart of a dying star. Thor's mystical hammer Mjölnir, which resembles a mallet rather than a war hammer, is stupendously powerful, rivalled only by Gungnir as Asgard's most powerful weapon ever created. It has a number of elemental powers. It has been stated be Odin himself that Mjölnir's power has no equal. Mjölnir itself is extremely durable like the metal Adamantium, and combined with the various enchantments placed upon it by Odin, it is, for all intents and purposes, indestructible. It has deflected three blast from the Destroyer (which was able to disintegrate anything that it hit) and return the blast back into the Destroyer. Thor often uses the hammer as a physical weapon, with almost nothing being capable of withstanding a hammer blow or throw. A few examples of the abilities Thor has shown with Mjölnir;
 * Strength: Mjölnir is immensely powerful and thus possesses incredible strength, despite its size. Its strength is enough to shatter Frost Giants, subdue the Hulk and create violent shockwaves with a single blow. The hammer's strength is not entirely infinite, as Captain America's vibranium shield and Gungnir were both able to endure going blow-to-blow with it, albeit with immense shockwaves as a result. By gathering enough momentum, Thor could use this weapon to destroy powerful giants with a single strike.
 * Weather Control: Wielding Mjönir grants Thor the ability to control the base elements of a storm. It can control the elements and can create giant raging electrical storms complete with thunder, lightning, hurricane-force winds, tornadoes, tidal waves, earthquakes and torrential rains at a moment's notice. He summoned a class 5 tornado to battle the Destroyer, but making it so it did not damage the town that the Destroyer was attacking. His use of powerful lightning bolts allowed him to destroy a large piece of landscape in Johtunheim, blast away and incapacitate Loki as the latter was surrounding him with decoys, and even destroy multiple Leviathans moving through a Tesseract portal over New York. He is remembered in myth and legends by the mortals of Midgard as the Norse Thunder God who used Mjölnir to summon rain, wind, thunder, lightning and more.
 * Worthiness Enchantment: After Thor disobeyed Odin and nearly caused a war between Asgard and Johtumheim, Odin banishes Thor to Earth without his powers and places an enchantment on the hammer Mjölnir. "Who so ever holds this hammer, if he be worthy, shall possess the power of Thor." This enchantment surrounding Mjölnir prevents it from being wielded by anyone save those who have been found worthy. When Thor sacrificed himself to protect the New Mexico town and it's inhabitants from The Destroyer he proved himself worthy to wield Mjölnir and gained full use of his powers. He also used it to trap Loki on the Bifrost, as those who aren't worthy cannot lift it. Thor used this power to distract the Hulk in their battle, who became so focused on trying to lift the hammer that Thor was able climb onto his back and attempt to choke him into submission.
 * Mystical Link: Mjölnir obeys Thor’s commands as though it were alive. Mjölnir went to Thor when it was in a crater from miles away, it came to him in seconds. Mjölnir will return to Thor when he throws it at an opponent. Only a mystically enhanced Algrim proved strong enough to prevent Mjölnir from returning to Thor's hand instantly by applying vast physical strength on the hammer and thereby deflecting its path significantly.
 * Flight: Thor is capable of hurling Mjölnir with great force and, by holding onto the leather thong, is capable of flying through the air at tremendous speeds. How fast is not specified, but he was able to fly in Johtumheim to kill a Frost Monster, fly in the middle of a Class 5 tornado, fly from the small New Mexico town to the closest Bifrost site, fly from Heimdall's Observatory to the main hall of Asgard in seconds, and later from Asgard back to Heimdall's Observatory.
 * Energy Projection: With Mjölnir, Thor can project blasts, waves and bolts of electricity and lightning of various sizes and intensities. While the hammer can generate electrical energy, it can channel more energy from the lightning storms it creates to summon its lightning for powerful energy attacks. With Mjölnir, Odin projects a powerful beam of golden light, using it to take away all of Thor's superhuman powers and destroys what was left of Thor's armor after stripping much of it off of him, ultimately sending him flying into the Bifrost.

Appearances

 * Marvel Cinematic Universe (6 films)


 * Iron Man 2 (Cameo)
 * Thor
 * The Avengers
 * Thor: The Dark World
 * Avengers: Age of Ultron
 * Thor: Ragnarok
 * Avengers: Infinity War (Mentioned only)
 * Marvel Cinematic Universe (1 TV series)


 * Agents of S.H.I.E.L.D.
 * Season 1
 * "Pilot" (Recycled footage)
 * "0-8-4" (Mentioned only)
 * "The Well" (Recycled footage)
 * Season 4
 * "Hot Potato Soup" (Mentioned only)
 * Daredevil
 * "Daredevil Episode 1.04: In the Blood" (Referenced only)
 * Luke Cage
 * "Moment of Truth" (Mentioned only)
 * "Who's Gonna Take the Weight?" (Mentioned only)
 * "Just to Get a Rep" (Mentioned only)

Trivia

 * The only known beings in the Marvel Cinematic Universe who have been known to lift the hammer are Thor, Odin, and Vision. Those who have attempted and failed are Loki, Bruce Banner/Hulk, Tony Stark, James Rhodes, Steve Rogers (although he was able to move it) Clint Barton and various inhabitants of the New Mexico town in which Thor was exiled.
 * However, in the comics, Captain America was able to wield Mjölnir as it deemed him worthy.