Rotty's Mud bath (Patreon)

 Rottytops was always the adventurous type and liked to spend most of her  nights sneaking out to go skinny dipping.  However, she liked to live  dangerously and plain old lake water wasn't nearly exciting enough so  she sought the pits of bottomless swamp muck.  She loved the feel of the  gooey morass creep up her legs and envelop her body as she sunk ever  deeper.  She doesn't even mind going under since, being a member of the  undead, she's used to taking dirt naps; this one will just be much  wetter.
 

Of course, it wouldn't be nearly as much fun for her unless someone joined her...