so-and-so vs stinkpot

so-and-so and stinkpot both are nouns.

Word	Noun	Adjective	Verb	Adverb
so-and-so	Yes	No	No	No
stinkpot	Yes	No	No	No

As nouns, so-and-so and stinkpot are synonyms defined as:

so-and-so and stinkpot: a person who is deemed to be despicable or contemptible

Other synonyms of so-and-so include bum, crumb, dirty dog, git, lowlife, puke, rat, rotter, scum bag, scumbag, skunk, stinker.

so-and-so (noun)	stinkpot (noun)
a person who is deemed to be despicable or contemptible	small freshwater turtle having a strong musky odor
	a person who is deemed to be despicable or contemptible