When an actor takes on a role in a comic book movie, he or she signs up for more than the normal challenges associated with filmmaking and must embody a character beloved and obsessed over by fans for years (sometimes decades). The stars of "Thor" had more than their fair share of mythology to absorb before production began, save for Kat Dennings, whose character Darcy didn't exist prior to the movie.

When MTV News caught up with a few of the "Thor" players, we asked them to give us a brief "character 101" for those not familiar with the world of Asgard and the god of thunder.

"Odin is just god of the universe," Sir Anthony Hopkins said of his powerful character. "The father of Thor. That's all I know." He also admitted that, try as he might to understand the complex Nordic mythology, he didn't delve too deeply into it.

Tom Hiddleston, who plays Thor's underappreciated and overlooked brother Loki, had a little more to say about what his character is working with.

"Loki is the god of mischief, the Norse god of mischief. He's a prankster, he's a trickster, he's an agent of chaos," he explained. "A behind-the-curtain puppet master, pulling the strings of the universe. He's also Thor's brother, and he's betrayed and has a sort of suitcase of pain that he's carrying around the whole time. He's damaged, lost and alone and vulnerable."

Aww. But before you go feeling sorry for Loki, don't forget about his powers. "When he's that intelligent and that good at magic, you don't want to piss him off," Hiddleston advised.

"Darcy is Jane Foster [Natalie Portman]'s assistant and kind of her intern and little-sister figure," Dennings said. "But she's really bad at her job. She mostly just staples things and makes food and drives, but with love."

"Lady Sif is Thor's right-hand man," actress and Jaimie Alexander said. "She's his childhood friend and accompanies him into battle and protects him at all costs.

Alexander added that Sif is the only one who will challenge the haughty Thor about being too cocky. "I think that's the fun thing about Sif," she said.

Check out everything we've got on "Thor."

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