more important details about the bots and other things in the comments. i suggest sorting by oldest first

So, the PB (pxxn bots) generally have a female-sounding name and yellow icons. The names often sound like "EllieElise8574". Whoever is making them is very fast because they show up quite quickly. They often follow some of the major streams (I moderate frontpage, WhenYourOutOfStreams etc so I get notifs when one of them follows those streams. They also seem to like to follow MS_memer_group/msmg even if they don't do shxt there.
Their comment formats are generally pretty much the same, like:

"Local single moms need anonymous SEX! Send a message and ask to F**K!

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*insert link here*"

"I've been a bad girl! Punish me here!!! -> *t.co/placeholder-link*"

"Want to see her ha**y va**na ass? Click here!!
<insert imgflip link repeated multiple times>"

so that's the basic gist of it. They like to pose as females and prefer irl pxxn (from the sole image I had to report of theirs). I have a suspicion that Mr.Walrus is behind these bots. (He deleted, but he owned all the bunni_porn alts [bunniporn is a probable-bot that likes to spam necro-pedo porn.)

another thing:
i've noticed that in the streams "anonymous" and "unsubmitted_images" are where porn posters like to post. I've had to report pxxn from anonymous stream.
also, the hornystream users (especially jeffery-!) like 2b2tmsmg because the rules allow porn. (the owner of the stream hasn't updated the rules, because they just forgot the stream)