Synonyms and related words :
barnacle, bedbug, blackmailer, extortioner, extortionist, freeloader, hanger-on, harpy, leech, lounge lizard, moocher, mosquito, parasite, predator, profiteer, racketeer, raptor, scrounge, scrounger, shakedown artist, shark, spiv, sponge, sponger, sucker, tick, vampire, vulture, wood tick