I'm convinced it exists, because I have actually seen it.
We were on holiday in Canada a few years ago and went on a sightseeing trip to a nearby lake, it was very placid with hardly any breeze and there was snow on the ground.
As we sat having a hot drink from our flask, we could hear rustling noises from the forest directly behind us.
On turning round we saw this giant figure staring at us and at the same time moving very slowly between the trees.
It must have been about fifteen to twenty feet in height and just seemed to disappear into the darkness of the forest.
About thirty minutes later, after we were sure it had gone, we plucked up enough courage to go and investigate where we had first seen it.
There were massive footprints everywhere, about three feet in diameter, with the impression of about fifty toes on each of them, an amazing sight that I will never forget.
I'm sure this creature was just curious and would not have caused us any harm, but we were just glad to get back to our hotel.
We never mentioned it to anyone whilst on holiday, but we did find out later, that ours was the third sighting that year.
You hear so many stories about mythical monsters and suchlike, but the last thing you expect, is to be confronted by them.