Ancient Picts - Pictish warriors often painted their bodies with a blue dye from a plant called "Woad". The woad would be painted in different shapes, such as animal. They were very fierce fighters, and the Romans feared them. Sometimes Celtic warriors would enter battle wearing nothing but woad and a necklace. This necklace would supposedly hold healing powers.
...those of the Quendi that came into the hands of Melkor were put in prison, and by slow arts of cruelty were corrupted and enslaved. And thus did Melkor breed the hideous race of the Orcs in mockery and envy of the Elves, of whom they were afterwards the bitterest foes. And deep in their dark hearts the Orcs loathed their Master.