The Collaborative International Dictionary of English v.0.48:

mimer \mim"er\, n.
   1. A person who performs in a mime.

   Syn: mime, mummer, pantomimer, pantomimist.
        [PJC]

   2. A mimic.
      [PJC]

The Collaborative International Dictionary of English v.0.48:

Mime \Mime\, v. i.
   To mimic. [Obs.] -- Mim"er, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

mimer
    n 1: an actor who communicates entirely by gesture and facial
         expression [syn: mime, mimer, mummer, pantomimer,
         pantomimist]

Moby Thesaurus II by Grady Ward, 1.0:

75 Moby Thesaurus words for "mimer":
   Roscius, actor, actress, antagonist, ape, bad guy, barnstormer,
   character, character actor, character man, character woman,
   child actor, conformist, copier, copycat, copyist, counterfeiter,
   cuckoo, diseur, diseuse, dissembler, dissimulator, dramatizer,
   echo, echoer, echoist, faker, feeder, foil, forger, heavy, histrio,
   histrion, hypocrite, imitator, impersonator, impostor, ingenue,
   juvenile, matinee idol, mime, mimic, mimicker, mocker, mockingbird,
   monkey, monologist, mummer, pantomime, pantomimist, parrot, phony,
   plagiarist, playactor, player, poll-parrot, polly, polly-parrot,
   poseur, protean actor, reciter, sheep, simulator, soubrette,
   stage performer, stage player, stooge, straight man, stroller,
   strolling player, theatrical, thespian, trouper, utility man,
   villain