Running around like a little Terrier, thinking it's tougher than whatever it might come across.
However, a few years ago a neighbor was walking a small, yippy dog through a wooded area near where I live. A coyote came out of the brush and before the neighbor could do anything, the dog took off after the coyote. The coyote disappeared back into the brush. Shortly thereafter a fair amount of barking, yelping, and growling was heard. The dog was never seen again.
Apparently the coyote saw the dog coming at it and thought "Hmm, it appears lunch is being delivered today!"