More details of Hob’s ‘Robin Redcap’, as found in Briggs’s ‘Dictionary of Fairies’:
One of the most malignant of old Border goblins, Redcap lived in old ruined peel towers and castles where wicked deeds had been done, and delighted to re-dye his red cap in human blood. William Henderson gives a full account of him in ‘Folklore of the Northern Counties’. He describes him as ‘a short thickset old man, with long prominent teeth, skinny fingers armed with talons like eagles, large eyes of a fiery-red colour, grisly hair streaming down his shoulders, iron boots, a pikestaff in his left hand, and a red cap on his head’. Human strength can avail little against him, but he can be routed by scripture or the sight of a cross. If this is held up to him he gives a dismal yell and vanishes, leaving one of his long teeth behind him. [It was Redcap who made Lord Soulis weapon proof, so that the only way to get rid of him was by boiling him in oil at Ninestane Rigg.]
Sounds ideal if you want to psychologically damage your children at this site or give them nightmares for weeks.