I was testing possible ways to have a feral Kenny in Second Life, and my current favorite is these animation overrides that you see me testing out here. It's the cheapest, least customization needed, and silly-looking. Other options look more feral, but also need extra texture work and cost a little more.
I couldn't afford the animations yet, even though it equals less than $2 US(Linden dollars are way cheap). Depositing more cash into my Second Life account just isn't a high enough priority at the moment, and having a feral fox is even lower priority. However, eventually I'd kinda like to go on a fox hunt in SL, and be the one hunted. Feral is more appropriate for that.