Here's what rhymes with quack.
alk whack wack back lack crack pack nach rack sac sack hack jack tack fac knack lac shack mac mak tak clack wrack yak claque mack yack black attack track stack plaque slack aback smack snack flak flack shellac unpack ipecac repack anorak rickrack highjack skyjack cardiac elegiac maniac zodiac piggyback gunnysack thumbtack pickaback mudpack paperback almanac quarterback hardtack haversack crackerjack razorback counterattack demoniac lumberjack stickleback amnesiac applejack insomniac steeplejack megalomaniac nymphomaniac Words that almost rhyme with quack
ag wag bag lag tag rag gag hag crag fag mag nag sag zag dag shag swag flag drag slag stag brag snag scrag washrag wigwag blag toerag dishrag fleabag chinwag scalawag nosebag scallywag sleazebag lollygag lallygag saddlebag ask anc ankh bank task rank tank thank mask sank crank cask masque shank bask dank hanc lank talc clank hank yank swank basque blank drank flank flask frank plank shrank franc prank spank stank unmask outrank embank charabanc riverbank antitank databank pointblank