The Jack-in-Irons

Jack-In-Irons (also spelled "Jack in Irons").

Jack in Irons (also spelled "Jack-in-Iron") is a mythical giant of Yorkshire lore who haunts lonely roads. He is covered with chains and wears the heads of his victims. He wields a large, spiked club.

His name may not be Jack as other Yorkshire folklore refers to "Jack-of-Green" and more so the name Jack may just be a term for calling the person an unknown male, like John Doe today.