Thor's Hammer, known as Mjölnir, is a powerful weapon in Norse mythology associated with the god Thor. It is often depicted as a short-handled hammer that can create thunder and lightning. Mjölnir is also a symbol of protection, blessing, and fertility, often used in rituals. In the myths, Mjölnir is so heavy that only those deemed worthy, like Thor himself, can lift it. The hammer is said to return to Thor after being thrown, showcasing its magical properties. Mjölnir remains a popular symbol in modern culture, representing strength and heroism.