someone who copies the words or behavior of another. [WordNet 1.5]

abyssinian cat, alley cat, angora cat, bear cat, bell the cat, big cat, black cat, blue cat, blue channel cat, burmese cat, caffer cat, calico cat, carbon copy, cat, cat and mouse, cat and rat, cat bear, cat box, cat burglar, cat chow, cat cracker, cat fancier, cat flea, cat food, cat o' nine tails, cat rig, cat scan, cat scanner, cat scratch disease, cat shark, cat sleep, cat squirrel, cat suit, cat thyme, cat valium, channel cat, cheshire cat, civet cat, coon cat, copy, copy editing, copy editor, copy out, domestic cat, draft copy, egyptian cat, fair copy, fat cat, fisher cat, flying cat, fossa cat, fraidy cat, hard copy, house cat, jaguarundi cat, jungle cat, kaffir cat, leopard cat, let the cat out of the bag, madagascar cat, maltese cat, manx cat, margay cat, marten cat, master copy, miner's cat, mud cat, native cat, pallas's cat, palm cat, panther cat, persian cat, prompt copy, review copy, ring-tailed cat, sand cat, scaredy cat, sea cat, siamese cat, soft copy, tabby cat, test copy, tiger cat, true cat, write copy, xerox copy