Thor

From beneath the cloth Brokk produced a hammer, and placed it in front of Thor.
Thor looked at it and sniffed.
"The handle is rather short," he said.
Brokk nodded. "Yes," he said. "That's my fault. I was working the bellows. But before you dismiss it, let me tell you about what makes this hammer unique. It's called Mjollnir, the lightning-maker. First of all, it's unbreakable—doesn't matter how hard you hit something with it, the hammer will always be undamaged."
Thor looked interested. he had already broken a great many weapons over the years, normally by hitting things with them.
"IF you throw the hammer, it will never miss what you throw it at."
Thor looked even more interested. He had lost a number of otherwise excellent weapons by throwing them at things that irritated him and missing, and he had watched too many weapons he had thrown disappear into the distance, never to be seen again.
"No matter how hard or how far you throw it, it will always return to your hand."
Thor was no actually smiling. And the thunder god did not often smile.
"You can change the size of the hammer. It will grow and it will also shrink down so small that if you wish you can hide it inside your shirt."
Thor clapped his hands together in delight, and thunder echoed across Asgard.