Source : Webster's Revised Unabridged Dictionary (1913)

Stooper \Stoop"er\, n.
   One who stoops.

Source : WordNet®

stooper
     n 1: a person at a racetrack who searches for winning parimutuel
          tickets that have been carelessly discarded by others
     2: a person who carries himself or herself with the head and
        shoulders habitually bent forward