Mjolnir is the enchanted hammer of the Norse god Thor, forged by the dwarven brothers Brokk and Sindre. It's a symbol of his power, used both as a weapon to smash enemies and as a divine instrument for blessing and hallowing. Mjolnir can also produce lightning bolts and is known for its ability to return to Thor after being thrown. In the Marvel Cinematic Universe, Mjolnir is a powerful weapon that can only be wielded by someone deemed worthy.