In the Marvel Comics universe, Thor is the greatest warrior in Asgard. With the mystical hammer Mjolnir given to him by his father, King Odin, Thor can command the weather, hurl lightning bolts, fly through the air, and smash through just about anything that gets in his way. But the god of thunder doesn’t always fight alone.

With buzz growing about the upcoming movie starring Chris Helmsworth in the title role, we thought it was time to take a look at some of the supporting cast from the film — namely, Thor’s greatest allies.

Just in case you're new to the world of "Thor," here's your guide to the characters he calls upon when even the might of a Norse god isn't enough to save the day.

[UPDATE: "Thor" trailer images removed.]

A childhood friend of Thor’s, Sif grew up to be one of Asgard’s fiercest warriors. Though she loves Thor, she knows that his love and loyalty to Earth would come before her — and so they’ve been friends as well as lovers, depending on the circumstances.

With her incredible sword-fighting skills, Sif has fought not only frost giants and other mystical enemies of Asgard, but also supervillains and alien warriors. She’ll be portrayed on-screen by actress Jaime Alexander.

In the comics, when Thor was living as the human doctor named Donald Blake, he met Jane when he hired her as a nurse. The two fell for each other and Don later revealed his double-life as Thor to her. The life of a thunder god isn’t an easy one, though, and eventually the couple split up.

Years later, Jane became a doctor and earned a reputation as a trusted consultant to superheroes such as Iron Man. When Thor was believed dead, Jane married, but then she divorced her husband when the thunder god turned up alive again. She remains one of Donald Blake’s best friends, and in the film she’ll be played by Natalie Portman.

Asgard had a few warriors in classic mythology, but Stan Lee and Jack Kirby wanted to add to the cast. They came up with a trio of new characters who would basically be modeled after the Three Musketeers, but with Asgardian strength. Fandral the Dashing, Hogun the Grim, and Volstagg the Voluminous make up The Warriors Three — and they have gained many fans over the years by kicking butt and taking names both on their own and alongside their thunder god buddy.

In the upcoming movie, Volstagg will be played by Ray Stevenson and Fandral will be played by Joshua Dallas. Unlike his two friends, Hogun is actually not native to Asgard, and in the film he will be played by Tadanobu Asano.

To get to Asgard, you need to cross the rainbow bridge called "Bifrost." And standing on Bifrost, on the borders of Asgard, is the ultimate watchman, Heimdall. With his godly sight, Heimdall can see across planets to find whoever he’s looking for, and he can detect an invading army when they are hundreds of miles away.

One of Odin’s most trusted warriors, Heimdall once served as interim king of Asgard when its true ruler knew he would be incapacitated. Heimdall will be played in the upcoming film by Idris Elba.

Thor might be Asgard’s fiercest warrior, but its noblest was Balder the Brave. Blessed with near invulnerability, Balder is Thor’s half-brother and once served as king of Asgard when Odin was away. Recently, he’s taken the throne again since Thor is not available for the job.

A peaceful and sensitive man at heart, Balder hates battle but never shirks from it, either. At this time, it’s not known if he’ll show up in the upcoming movie.

Anyone else you'd add to the list? Let us know what you think in the comment section or on Twitter!