You know anything with “flesh” and “dreg” in the name just didn't work out right the first time. I guess even evil needs a rough draft.
Fleshdregs are what happens when sinspawn creation fails, being little more than mouths, legs, and their associated sin. While not very powerful in general (CR 1), their special abilities can still really do a number on the low-level PCs they’re meant to face.
Of course, fleshdregs don’t have to be failed experiments in your campaign; as aberrations, they might even be (semi)natural. For instance…
A new adventuring party escorts their novitiate cleric friend to his first placement, only to find the parish priest he was to serve has disappeared. That night, a strange wave of energy ripples through the town, causing hitherto unnoticed pods to swell and burst forth fleshdregs. The aberrations represent a variety of the community’s sins—several local barns birth lust fleshdregs, for instance, while envy and wrath fleshdregs pop up behind the rough public house—and they eagerly attack the humanoid sources of the sins they embody.
A greedspawn despises the clamoring greed fleshdregs that tail her every move, but her nature simply won’t allow her to part with any of them. If adventurers wound or even kill the fleshdregs she is unconcerned, but if they use any kind of mind-affecting, enchantment, or similar spell on the fleshdregs she will become incensed, screaming “Mine! They are mine!” in Aklo as she attack the culprit in a rage.
Adventurers are visiting a local mage. He expresses interest in tutoring one of their number within earshot of his oft-overlooked assistant. The apprentice’s envy imbues the cauldron she is stirring, hatching a well-nurtured and fully grown fleshdreg before the company’s very eyes.
—Pathfinder Adventure Path #61 82–83 & Pathfinder Bestiary 4 100
Want more fleshdregs? Try a freshdreg swarm, courtesy of Pathfinder Adventure Path #61: Shards of Sin!
I like fleshdregs and sinspawn. I don't want every campaign feeling like the Bible or the Inferno, but I do like campaigns where sin is a real thing. (After all, sin magic helped put Rise of the Runelords—and Pathfinder—on the map.) And I’m sure you could substitute various shades of shame or dishonor if sin isn't your thing.
Since with my schedule I struggle to read the official Pathfinder books in a timely fashion (the softcovers I’m solid on; the hardcovers are another, far sadder story), I’ve never given the fan-produced Wayfinder the attention it deserves (and it truly does deserve it). I’d be remiss if I didn't point out that issue #12 is out today, though.