WordNet (r) 3.0 (2006):

stooge
    n 1: a person of unquestioning obedience [syn: flunky,
         flunkey, stooge, yes-man]
    2: a victim of ridicule or pranks [syn: butt, goat,
       laughingstock, stooge]
    v 1: cruise in slow or routine flights
    2: act as the stooge; "His role was to stooge for the popular
       comedian"
    3: act as a stooge, in a compliant or subordinate manner; "He
       stooged for the flamboyant Senator"

Moby Thesaurus II by Grady Ward, 1.0:

225 Moby Thesaurus words for "stooge":
   Charlie McCarthy, Roscius, act, act as foil, actor, actress,
   adherent, agent, also-ran, ancilla, antagonist, appear, appendage,
   apple-polisher, appliance, ass-licker, attendant, babe,
   backscratcher, backslapper, bad guy, barnstorm, barnstormer, boob,
   booby, bootlick, bootlicker, brown-nose, brownie, buff,
   cavaliere servente, character, character actor, character man,
   character woman, child actor, chump, cinch, clawback, come out,
   contrivance, courtier, creature, credulous person, cringer, cull,
   dangler, defeatee, dependent, device, disciple, diseur, diseuse,
   dramatizer, duck, dummy, dupe, easy mark, easy pickings, emote,
   emotionalize, fall guy, fan, fawner, feeder, feudatory, figurehead,
   fish, flatterer, flunky, foil, follower, following, fool,
   footlicker, front, front man, game loser, get top billing, gillie,
   go-between, gobe-mouches, good loser, good sport, goon, greener,
   greenhorn, greeny, groveler, gudgeon, gull, handmaid, handmaiden,
   handshaker, hanger-on, heavy, helot, henchman, histrio, histrion,
   homager, homme de cour, implement, inferior, ingenue, innocent,
   instrument, interagent, intermediary, intermediate, intermedium,
   jackal, juvenile, kowtower, lackey, lay figure, leadpipe cinch,
   led captain, lever, lickspit, lickspittle, liege, liege man, loser,
   man, matinee idol, mealymouth, mechanism, mediator, medium,
   midwife, mime, mimer, mimic, minion, monkey, monologist, mummer,
   myrmidon, nominal head, organ, pantomime, pantomimist, parasite,
   partisan, patsy, patter, pawn, peon, perform, pigeon, play,
   play the lead, playact, playactor, player, plaything, prize sap,
   protean actor, public, puppet, pursuer, pursuivant, pushover,
   reciter, register, retainer, sap, saphead, satellite, schlemiel,
   sectary, serf, servant, shadow, sitting duck, sketch, slave,
   soubrette, spaniel, sport, stage performer, stage player, star,
   steal the show, straight man, stroller, strolling player,
   subordinate, successor, suck, sucker, supporter, sycophant,
   tagtail, tail, the vanquished, theatrical, thespian, thug,
   timeserver, toad, toady, tool, toy, trainbearer, tread the boards,
   troupe, trouper, truckler, trusting soul, tufthunter, underdog,
   underling, understrapper, upstage, utility man, vassal, vehicle,
   victim, villain, votary, ward heeler, yeoman, yes-man