Ancient Celts - Celtic warriors often painted their bodies with a blue die 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.
In English folklore, a boggart (or bogart) is a household spirit which causes mischief and things to disappear, milk to sour, and dogs to go lame. Always malevolent, the boggart will follow its family wherever they flee. In Northern England, at least, there was the belief that the boggart should never be named, for when the boggart was given a name, it would not be reasoned with nor persuaded, but would become uncontrollable and destructive.