The Collaborative International Dictionary of English v.0.48:

Stuffer \Stuff"er\, n.
   One who, or that which, stuffs.
   [1913 Webster]

WordNet (r) 3.0 (2006):

stuffer
    n 1: a craftsman who stuffs and mounts the skins of animals for
         display [syn: taxidermist, animal stuffer, stuffer]
    2: an advertising circular that is enclosed with other material
       and (usually) sent by mail