I'll give you anything! Just return my rifle, I beg you. I lost it by that place where those damn bloodsuckers live. Here are the coordinates. Be careful though. Bloodsuckers aren't the friendly kind.Hunter
A short bio, that was being omitted from final version of S.T.A.L.K.E.R.: Shadow of Chernobyl game describes him as follows: 
Shadow of Chernobyl
Hunter hangs out in the 100 Rads Bar and can give the player two unique missions:
- He shares a name with a character from the book Metro 2033.
- After Marked One complete the only one quest offered by him, this weapon would probably became his primary weapon.