Create an image of a Nac Mac Feegle, a small, blue-skinned, red-haired character from Terry Pratchett's Discworld series. The Nac Mac Feegle should have a wild and fierce expression, with bright, fiery red hair sticking out in all directions. They should be dressed in a traditional kilt made of rough tartan fabric, with a small, crude sword or dagger in one hand. The character should appear muscular and wiry, with a mischievous and bold demeanor. He should have bare arms and chest. The background should evoke the Scottish Highlands, with misty hills and a sense of ancient mystery.