It was probably a harpy. Those things have no chill.

I got accidentally attacked by a hawk of some sort. I was walking on a university campus pathway and got thwacked by a hawk jumping off of a pole. Turns out I was merely between it and its prey - it was about to swoop a squirrel. It bounced off me, ignored my existence entirely, and kept chasing the squirrel. Knocked me a bit off balance, but the bird appeared fine and so was I.