Thor

"“Well, mortals, it's a good thing we arrived when we did, or that giantess might have hurt someone!"

- The Hammer of Thor Thor (ON: "thunder") is the Norse Æsir god of thunder, strength, fertility, and consecration, and is physically the strongest of the Æsir. The son of Odin and Jörð, he is married to the Norse goddess Sif. He was known as Thunor to the Anglo-Saxons, and Donar to the southern Germanic peoples. His symbols of power include the lightning bolt, hammer, axe, and club, goats, and oak trees.

The Sword of Summer
The thunder god is first seen in Jötunheimr being drowned by a female jötunn, whom Jack quickly slays. Thor then invites them to dinner and sends Magnus and his friends on a quest to find his "not officially missing" hammer Mjølnir. After the group kill the giant Geirrod and his daughters Gjalp and Greip, Thor then appears on his flying chariot (having sensed Gunilla's presence), much to their annoyance. He accepts his staff and send the four to where each of them needs to be, but not before asking the group to not tell anyone about Mjølnir being missing, especially his children.

The Hammer of Thor
When Magnus meets one of Thor's goats, Otis, at the Thinking Cup on Newsbury Street, he learns that Thor's hammer is still 'unofficially' missing. Magnus later discusses with Sam, the movements of the jǫtnar in preparation to invade Midgard and that it is only their fear of Thor with his hammer that is preventing them from doing so.

When Magnus is sleeping in Hearth's house in Alfheimr, he has a dream about Thor in Jötunheimr, using Mjølnir to obliterate a thousand giants. Thor then looks directly at Magnus and tells him to hurry up with finding his hammer.

When Sif transports Magnus, Sam, Alex, Blitz and Hearth to Bilskirnir, her and Thor's palace in Asgard, she directs them to Thor's "man cave" to discuss their plan to retrieve his hammer. They explain that Mjølnir is to be used as the morning after  gift in the earth giant Thrym's marriage to Sam. Thor says that the bride has the right to insist that the gift be summoned in order to bless the ceremony and ensure that the hammer can be obtained. After they agree to infiltrate the wedding with Alex posing as Sam, Thor gives them his chariot to ride to the wedding. Thor explains he can concentrate to see through Otis and Marvin's eyes and that when the hammer is summoned by Thrym, he will lead a squad of gods and einherjar underground to retrieve the hammer and slaughter the giants. He then gives Blitz and Hearth "Thor's Hall Pass" in order to allow them to enter Valhalla and alert the einherjar to the plan.

Later on, Thor, along with Heimdall and Vidar, manage to break into Loki's Cave after Loki has been freed. Thor retrieves Mjølnir and vaporizes the giantess Thrynga with a blast of lightning from the hammer. After kissing and loving his hammer as if it was his wife, he then takes everyone back to Valhalla in order to celebrate the return of his hammer.

The Ship of the Dead
Thor, along with the other gods appear at the end of the book when Magnus and crew have captured Loki. They congratulate them and hold a party.

Appearance
Thor was described as a god with shoulder-length red hair, a curly red beard, bodybuilder arms, and hands the size of pot roasts. He wears a sleeveless leather jerkin, dark iron gauntlets (that are reminiscent of robot hands) and a hauberk (chain mail shirt). Thor's face is handsome "in a beat-up way", like he’d spent years in the boxing ring. Unlike his Marvel movie version, "there [is] nothing polished about [him]", since Thor is quite unkempt, with his hauberk being filthy, and his leather jerkin and trousers worn to the color of dirty snow. In addition, he also usually has goat grease in his beard, from eating Otis and Marvin so many times.

Thor has the name of his wife Sif tattooed on his left biceps inscribed inside a heart. He has a stylized tattoo of Jörmungandr the World Serpent coiled around his right forearm. Across his knuckles on either hand, in block letters, are the names of his sons Modi and Magni.

Abilities
The Norse god of thunder, and possibly the strongest of the Æsir, Thor is one of the most powerful gods in existence, his power is respected and feared in all the Nine Worlds, so much, that Magnus Chase stated that the only reason why the jǫtnar (giants) had not invaded and destroyed Midgard yet, is because they fear Thor's wrath may fall upon them.
 * Massive Strength: As the God of Strength, Thor has incredible super strength, being the strongest of the Norse gods. Just a light clap on the shoulder from him dislocated several of Magnus' joints. When wielding Mjölnir, he is strong enough to blow up an entire mountain, along with an army of giants, with just one hit from his hammer.
 * Electrokinesis: As the God of Lightning, Thor has absolute control over electricity and generates electrical sparks from his hands, ears, and rear when excited.
 * Atmokinesis: As the God of Storms, Thor has absolute control over storms.

Attributes
Thor's primary attribute is his mighty hammer Mjølnir, the most powerful weapon in all of Norse mythology. His other attributes include his iron gauntlets Járngreipr (which he is required to wear while handling his hammer), and his magic belt Megingjörð (which doubles his strength when he wears it), as well as the mighty Bone Steel staff, Gríðarvölr, his secondary weapon (used when he loses his hammer).

Attendants
Thor has two loyal attendants: the goats Tanngnjóstr/Otis and Tanngrisnr/Marvin, who pull his chariot. They are killed and eaten by the god every evening, with them always resurrecting the next morning. He is also frequently accompanied by his regular manservant, Thjalfi, though Thor granted him a furlough due to the stress shortly before The Sword of Summer.

Trivia

 * While Mjølnir is commonly depicted as either a simple blacksmith's hammer (Prose Edda and Poetic Edda) or an uru clubhammer (Marvel), it has been primarily depicted as either a wooden club or a mounted stone axe since as early as the Teutonic tribes. Even as late as the Viking era, the axe, wooden club, and hammer were all interchangeable depictions for Mjølnir.
 * Thor's Greco-Roman counterpart (in terms of his primary domain) is Zeus/Jupiter (thunder, lightning, and storms). He also shares domain with Hercules (strength), Aphrodite (fertility), and no specific counterpart his status as god of consecration.
 * Thor watches a lot of Midgard (human) television. Some shows he watches are Arrow, Breaking Bad, Game of Thrones, and The Walking Dead.
 * Thor has lost his hammer Mjølnir three times.
 * During the events of Ragnarök, Thor is destined to kill Jörmungandr, the World Serpent, but to be slain himself by Jörmungandr's venom as it dies. He will take nine steps before dying.
 * The weekday Thursday (derived from Old English Þūnresdæg; originally Torsdag (Þorsdagr) in Old Norse) is named after him.
 * The Rune representing Thor is called Thurisaz.
 * Tacitus, a Roman historian and senator, associated Thor (specifically, his Germanic persona, Donar) with the Greco-Roman hero Hercules/Heracles.
 * Thorium, a chemical element discovered by Swedish chemist Dr. Jöns Jacob Berzelius in the early 19th century, is named after him.
 * In the Swedish island of Gotland, a species of beetle (scarabæus stercorarius) was named after the god; the Thorbagge.
 * Thor's hero shrew (Scutisorex thori), a species of shrew native to the Democratic Republic of Congo, is named after him, due to him being associated with strength.
 * The Swedish death metal band Amon Amarth's 2008 studio album Twilight of the Thunder God is based around Thor's slaying of the serpent.
 * In Sweden in the 19th century, smooth, wedge-shaped stones found in the earth were called Thorwiggar ("Thor's wedges"), according to a folk belief that they were once hurled at a troll by the god Thor.