Praise the Grandfather!

On the bright side, that fluffy likely won’t suffer at least not past the initial horror of seeing a creature like that. Nurgle is perhaps the most affectionate of the chaos gods and likes to grant certain boons to those who give themselves over to him. In particular he tends to grant immunity to diseases and makes the the subject impervious to the discomfort from them (while making them a grotesque carrier of his choice of horrific diseases).
 
The fluffy will probably offer friendship to Nurgle and choose/accept offers to serve him (read: be his fwend). It’s virtually guaranteed that the fluffy will end up being made a champion of Nurgle given how effective one one be in spreading Nurgle’s “gifts”.
 
Next thing you know there’s an immortal, eldritch-ish fluffy pony going around spreading diseases too horrible to imagine. Plus every time an abuser kills it, the fluffy would likely explode in a cloud of disease spreading germs/bacteria. Then Nurgle would just resurrect his fluffy champion and the process would continue.