harasser - a persistent tormentor

oppressor - a person of authority who subjects others to undue pressures

blighter, cuss, gadfly, pest, pesterer - a persistently annoying person

tantaliser, tantalizer - someone who tantalizes; a tormentor who offers something desirable but keeps it just out of reach

witch-hunter - someone who identifies and punishes people for their opinions

flat - scenery consisting of a wooden frame covered with painted canvas; part of a stage setting