Hmm, dunno really.
I'd say either two-humans or cursed lusts.
Two-humans are from the RAW travesties thread - literally two humans of different gender fused together by their backs, who walk around like crabs and live in forest retreats. What's funny, is that while they started as just a one-off thing I did for the thread, I eventually gave them a civ and started to think of story-wise explanations for why these abominations of nature even exist - they worship gods of things like blight, deformity, disease, nightmares, etc. and I sorta imagine them to be made by those gods as mockeries of normal humans.
Basically "great old one" type stuff - their language I generated with the "Lang Create" utility is also pretty harsh-sounding when spoked out loud (funnily enough, the word it generated for "witch" is "vader" - not the first time I had either a name from some other work of fiction or a real word being generated - the earliest language for nagas I generated had the word "grasp" be translated into "naga" as "ass" - removed it pretty much immediately, even though it made me chuckle, especially with the associated word).
Cursed lusts are representations of lust (part of 5 different megabeasts based on the Seven Deadly Sins motif - I still have to do Envy and Greed, though) and are humanoids with a large, hanging tongue, several grasping, clawed tentacles sprouting from it's back (I didn't want them to have fingers but as this was a very early mod I made I didn't know the game would attach them to the tentacle claws as well - left it in since the resulting mental image was pretty creepy) and grotesque tumors on certain parts of the body.
Depending on the gender they also have a unique body part - a large swollen member for the males and tumorous mammaries for the females (I can't believe I wrote that).
They also can spray white-coloured fluids (yes, it's exactly what you think it is) with those body parts that cause different syndromes, varying on the gender - females cause bleeding, nausea, dizziness, coughing and vomiting blood, whereas males cause swelling, necrosis, bruising, blistering and dizziness (what do you mean "is it supposed to be symbolic?"). Also gods might occassionally transform you into one for toppling their statues.
You may throw up now.
I haven't separated the raws for them from my other stuff, though, currently I only have the entirety of all my mods uploaded onto dropbox along with some of the other RAW travesties creatures that were made by other users in that thread.