Few years back we had one about 14-16 inches across it's shell laying eggs in out backyard.
My 40 pound dog went up to it, and stuck her nose in it's face to smell it.
I was across the yard, and unaware of the turtle at the time. I heard a yelp, of both pain and surprise, turned in time to see both my dog and something big and black, landing.
The turtle must have grabbed hold of her, and she jumped, turtle and all.