Riddler rhymes with:
kridler, kridler, midler, adler, andler, bendler, chandler, chudler, edler, endler, fedler, fendler, fiedler, findler, gendler, handler, hendler, kandler, kridler, laidler, landler, lindler, mandler, medlar, medler, midler, oddler, panhandler, peddler, raedler, redler, sadler, sandler, schindler, schundler, sedlar, sedler, seidler, shindler, stadler, tendler, toddler, wandler, wendler, windler
Riddler sounds like:
radler, raedler, rattler, redler, retailer, ritthaler, roethler, rothweiler, rototiller, rottler