WARNING: GROSS STORY FOLLOWS
Reminds me of the story of a homeless man found dead in his shelter near the Sumida River a few years ago. He wasn't discovered for a few days. Since he was homeless and unemployed, it took a while for anyone to miss him. And since he lived in an area with lots of those little blue shelters, it took a few days for the unique odor of rotting human flesh to rise above the other various smells.
When he was found, he was naked from the waist down and there was extensive damage to his groin. A large amount of flesh was missing from that area. Just gone. Disappeared.
Police suspected that he had been murdered by a pervert who had mutilated the body, removing the genitals and some of the surrounding flesh. Since such a psychopath could reasonably be expected to commit a similar crime again, they feared they might be looking at the first efforts of a potential serial killer. Naturally, they didn't look forward to either the crimes, the publicity that would surround them, or the huge investigative effort that they would have to mount.
Fortunately for them, the pervert was soon identified.
The pervert was the victim himself.
It seems there were lots of stray cats in the area. With the resourcefulness many unfortunate homeless souls display in their struggle to stay alive, he had learned to put the stray cats to use. He ate canned tuna and smeared the leftover oil on his John Thomas to entice the cats to give him a tongue job.
The last time he did it, though, he had a heart attack and died. It wasn't long before the cats decided he would make a good source of meat protein. From habit and from the smell of the tuna oil, they concentrated their efforts in his groin area. They managed to eat away a pretty good bit before the man was discovered.