Well, my first experience was a 3 day old semi-liquified rat. I described it as the "most intense imaginable soy sauce scent" as the odor was orders of magnitude more pungeant, but had that fermentation overtone. With the second occurance being the Sav's rats the other day.
Although I do know another dead animal stink that is completely unlike my experiences with rats. That was like a strong mold, liquified meat, fermented flesh, vomit smell. That actually caused a lot of mental and ol'factory distress