Deadman is a main character in Death Stranding. He appears to be involved in the medical field for Bridges. He is an artificial human, created from a combination of cadavers and stems cells. The origins of Deadman are unclear, although it is known that 70% of his body was harvested from cadavers, while the remaining 30% was grown from pluripotent stem cells.

Deadman is affable and well-meaning. However, he is ashamed of his nature as an artificial human, calling himself "Frankenstein's monster". This has instilled a great deal of loneliness in him, and he reaches out to Sam as a result. Deadman expresses his loneliness to Sam saying he has no wife, no children, and no friends, but only until he meets Sam things start to change.

Deadman is "Frankenstein's monster, I have no soul, no beach. that's why I try to connect myself with you. I am a Deadman."

Source: https://deathstranding.fandom.com/wiki/Deadman