Had that happen a couple of years ago. Came around a corner in the country late at night and saw a bear cub in the middle of the road. Couldn't swerve and hit him dead center. My house was just a few hundred yards up the road so I went there and came back to pick up the cub - no cub! Next morning I went out to check my bike and go look for the cub. Big surprise. The front wheel was cover with porcupine quills!

Biggest damn porcupine I ever saw.