I've actually had the priviledge to both see and smell gangrene once, and that looks like the real deal to me. The person who is lucky enough to have gangrene must have ignored it for a long time though... See the way the skin has rotted away over the wrist and you can see the tendons? Sexy stuff.
Let me tell you something, the smell is the worst thing I have ever smelt in my life. Just thinking about it is almost enough to make me throw up, and I was standing a couple of metres away in my experience of it. There's no smell like it in the world.
I agree, tis a smell like no other. I wish that lynx would create such a gangrenous odour, for I smell much worse.
