I like the possible implication you came up with for Option 4. A slightly stronger digestive system might just give it the edge it would need for it to subsist on some forms of plant matter which might be too inedible for regular fluffies, but is just edible enough for a poopie fluffy to digest, even if only partially.
And honestly, there are probably predators that would be more interested in eating a rich, fatty bestest babbeh than something with very little meat on it, which also probably smells like it would make them ill. Hell, even if it stopped smelling like shit, the duller coloration probably would be advantageous in terms of stealth and survivability compared to the bright and obvious coloration of a bestest babbeh.
He’s sweet. I hope he escapes, even if it’s just to live on his own for a bit. He’d be a perfect fit for my forest herd of Brown and “Ugly” fluffies who banded together to survive in the woods, that’s for sure!
Option 4 seems feasible. Bonus if there are extra vitals that are discharged via piss. I’d imagine that’s where most chirpries start; by liking up the pee.
Muted fluffs feel more like they would be an actual animal to me, and if Fluffies began as creatures mutated and altered by Hasbio instead of being made semi-wholecloth: A “poopie” fluffy would probably be closer in appearance to their original stock.