I once picked up a heavy duty poly bag near West Drayton on the South GU. It was very dark and cold that night and as I cut the bag away, in the light of the torch, I saw pink flesh with white bone sticking out. I investigated further and found that it was the remains of a pig's carcass, but it gave me one hell of a scare.

Another incident - again in the dark, reminded me of the scene in "Twenty Thousand Leagues under the Sea" where they fought the giant squid. The "tentacle" that reared up in the weed hatch turned out to be a piece of slimy 4" polythene tubing - there was about 4m of it - it was very useful for all sorts of jobs once I cleaned it up !