Here me out.

It's a snake made out of diaper material (like a diaper critter but not anthro), with the underbelly being the absorbent part and the back being the shiny outside. It's usually colored a combonation of light blue and white, but variations can occurr. It actively hunts anything with two or more legs, be them feral or anthro.
When it finds a victim, it gives them a paralysing bite, then wraps itself around their crotch and butt (similar to a diaper made of vines). Its head ends up around where the tapes would normally be on a diaper, giving it a good view of the surroundings. The snake is sustained by being used, so to encourage the victim it bites them again, this time using a different poison that both makes the victim hungry and acting as a laxative. Once the victim uses the snake-diaper, it gives a reward by massaging the victim by contricting lightly.
The snake grows when it eats, making it longer and thicker, therefore thickening the victim's "diaper". Once its length has doubled, it removes itself from the victim and seeks a bigger target. The victims are usually left incontinent after the encounter.

NAME IDEAS: Death Padder, Poof Adder, Cottonmouth (made of cloth), Black Mamblort, Aspamp

Inspired by this (marked as adult but not very gnarly):https://www.furaffinity.net/view/32789493/

This had to be its own journal because it's much more complicated than other diaper ideas I've had for drawing. Just thought someone would be interested.