Here's what rhymes with mastodon.
upon don dawn baton bon pawn bonne john non drawn gone von con lawn yon hon wan fawn han schon spawn yawn khan sawn sonne vpon brawn pecan prawn faun gnawn undergone thereupon salon swan yuan npon octagon operon begone hereupon tenon antiphon hereon predawn autobahn lasagne methadon thereon whereupon automaton foregone positron whereon echelon exon fagon paragon redrawn chaperon chiffon forgone overdrawn aileron amazon epsilon tarragon upsilon outdrawn withdrawn polygon denouement pantheon hexagon marathon pentagon woebegone carillon leprechaun heptagon neocon trimaran emoticon frogspawn phenomenon cordovan lexicon rapprochement pantechnicon Words that almost rhyme with mastodon
bomb palm bom balm tom dom dong pom pong tong bong long along wrong com song calm mom homme vom gong nom rom som mam prom prong thong aplomb twang iamb firebomb strong belong quam prolong throng ftrong suam pogrom embalm qualm salaam sarong erelong mahjong becalm dingdong supermom intercom singsong consomme nightlong lifelong cardamom yearlong livelong born borne torn barn adorn darn porn tarn corn worn horn warn yarn morn mourn thorn unborn shorn lorn scorn sworn forlorn reborn firstborn outworn stillborn waterborne forborne unworn lowborn forewarn peppercorn timeworn sweetcorn careworn forsworn lovelorn foresworn unicorn