Greybacks real name is actually Predator 1718 or to be more precise, the Golden Angel!
Biography
18th century
Greyback first visited Earth in 1718, when he encountered pirate captain Raphael Adolini and assisted him in fending off his mutinous crew. At the end of the deadly battle, Adolini gifted the Predator with his flintlock pistol before succumbing to a gunshot wound. Greyback then buried the captain and gifted the dead man with his otherworldly sword.