I

have never seen anything but can relay an unusual experience I did have.
I was camping in the Trinity Alps in 2016 with my brother and a friend. We made camp in a remote area that took most of the day to hike to. Sometime late in the evening we left our campfire and went into the tent for the night. Our fire had died down a lot and from inside the tent we could just barely see the glow from what fire was left. I was in the middle of the tent with my brother on my right and my friend on my left. Suddenly, the fire went from being nearly burnt out to shooting up around 6 feet in the air before quickly going back down. That got our attention pretty good and put us in high alert. We were whispering about what had just happened when something tapped on the left side of the tent multiple times in quick succession like someone knocking on a door. My friend came flying across the tent to the middle completely terrified. There was a pause for a few moments until it began playing with the zipper on the tent, flicking it back and forth. We had knives out and were ready for its imminent entrance but that never came. It played with the zipper off and on for a little while before it left. Years later I looked up that location on some bigfoot databases and learned that many other people had reported similar experiences in the area.