When I was a youngster me my bother and dad would go on a lot of beach walks along the coast near where I lived, we would always come back with neat stuff, sea junk, bird skeletons, animal skulls... There was always something interesting to be found.
On one of these occasions we started out walking along a beach we hadn't been to before, we all noticed a strange odder in the air, we continued walking and noticed in the distance a large number of sea gulls circling a small area of land right on the sea shore, so we went to check it out.
What we found was a large carcass, about the size of a killer whale, it was shaped like a banana with a fat middle, it had no discerning head, tale or flippers and was fully white. It reminded me of jelly and I remember being able to see its rib cage through its rotting flesh. I think we stayed around it for probably an hour trying to figure out what it was, but we couldn't.
We went on our way, had our day and passed it on the way back, there were two men around it at this time, they seemed to be as puzzled as we were. When we arrived home I asked my dad what he thought it was and he said "Taniwha".
To this day I still don't know what it was, we looked in the local papers to see if there was any mention of a beached whale or anything, but nothing. The conclusion I've accepted is that it was a Taniwha.
