I've taken a list of English words, and examined each of them to see what they sound like (using the PHP metaphone function). This page lists the most common metaphone codes, along with their words. You can also search for a word of your own, and see which words sound similar - and which ones rhyme, and which ones alliterate.
mutts muts mauts motts matts mutes mitts mottes mottos mattes mutase mats mots mottoes muds mauds metes modus motes moats mites mitis metis meats meets moots mates medusa matsah mateys medius meatus medusae metisse muddies moieties mads meds mids mods
butts mutts putts uts louts matts huts botts routes cutes cuts bouts bitts mottos rottes suets lottes suttas mutes duets puts beauts sautes pottos batts buts shuts tutus shouts chutes tots watts tets utes butes tats outs tuts mitts bettas autos routs nutsy netts dauts quits fouettes phuts ghettos cottas lottos mauts ruts tuttis lyttas knouts tauts setts dittos dattos mattes utas tits gutsy suits ghauts fyttes muts lutes pouts pittas ottos guts duits touts nuts mottes lattes cutis buttes gouts juts chotts motts shotts shutes jutes yetts
mutt mut matt matte maut mitt mott motte motto mute smut smutty