A Jack-in-Irons is a type of malevolent "ghost-giant" found in Yorkshire Folklore and is depicted as a large, often hideous man covered in chains who haunts lonely roads.
Armed with a spiked club the Jack-in-Irons preys upon unwary travelers and animals, beating them to death and taking their heads, which the monster then proudly displays on his chained form.
Cruel and murderous in nature a Jack-in-Irons delights in the suffering of his victim and is related to the ogre and the more vicious giants of folklore, though unlike them a Jack-in-Irons often displays a number of ghost-like powers in addition to his usual gruesome array of giant traits.