I had a very unusual experience with an octopus. A few years ago I visited Adriatic coastline. It was still too cold to swim, but warm enough to wade in the crystal clear blue water. At one point I looked down and to my amazement and shock an octopus attached itself to my leg.
I panicked and started to vigorously shake my leg. After a while I was able to get rid of the octopus. It was not that big, maybe a pound in weight. When I later told the story to a local fisherman he suggested that walking out of the sea would have been wiser, and at the same time I would have had something to serve at the diner table.
I don't think this will happen ever again, but if it does I will follow the fisherman's advise.