I don't have a picture of this as it unfolded, but within the last year I bought a nice Mobiloil Aero Green Band quart can off Ebay. It was a barn find and looked nice but needed a good cleaning. When I received it I unboxed it and it had a bit of an odor coming out of it but I was at work so I put it back in the box. When I got home that day I started to clean the can and the odor starting getting worse. The can felt like it had a little bit of extra weight in it, but it seemed to be stuck to the bottom of the can in the old gunk. I put some warm water in it and a bit of 409 cleaner to help cut the gunk, plugged the hole and vigorously shook it. Whatever was in there dislodged and I could feel it moving around. When I poured the water out I saw bits of fur, and the smell had gotten much worse! After a couple more cycles of this and more chunks of fur and flesh coming out the hole, a partially skeletal varmint leg poked out of the hole. I pulled on it and probably half of a dead mouse came out! I damn near threw up, it was nasty!! It wasn't recently deceased, but it wasn't petrified either. At least now I knew what I was dealing with and got the rest of it out, but darned if I don't think of that every time I look at this can now, haha!!
On a side note, the other cans I've had that the contents stink are the old Mobil Jet Oil synthetic oil cans from the 50's.....what a nasty smell they have, and tough to get rid of!