THESAURUS
trusting soul
babe, boob, chump, cinch, credulous person, cull, dupe, easy mark, easy pickings, fall guy, fish, fool, gobe-mouches, greener, greenhorn, greeny, gudgeon, gull, innocent, leadpipe cinch, monkey, patsy, pigeon, plaything, prize sap, pushover, sap, saphead, schlemiel, sitting duck, stooge, sucker, toy, victim