Thinking about it we’ve had a few incidents with fauna over the years. As well as the previously mentioned deer:
We once all climbed over a style into a narrow footpath (yeah, yeah…) it was a metre or so wide with a fence one side and a hedge the other and it was dark. The horse that had got out of its field and got stuck in it panicked by our lights charged us. We had nowhere to go! A few minor injuries and bits of damage from that one!
We had another deer which we accidentally cornered (again on a night ride) that charged and jumped over us.
On another night: my mate felt an impact and something clinging to his chest: on inspection it was a bat!
I came round a corner once to face a young badger hissing and spitting at me from about 3 feet away.
Found an adder happily basking in the sun right next to the start of a section of trail at Kirroughtree.
When doing a heli drop in Whistler we spotted a cat like creature sat on a rock some distance away. Someone asked “is that a cougar?” Our guide replied “No. That’s a bobcat. If you see a cougar? It’s too late!!”
I’ve seen plenty of other wildlife without incident (bears, foxes, owls, etc etc). Always a highlight in a ride.