Deer can do a lot of damage. There was an accident many years ago in FL where a car going north hit a deer, the deer crashed into a car heading south, went through the windshield, killed the driver, went out the back window and landed 30 feet down the road.
One of the scariest things I have seen driving, I was headed south on an interstate, on the right was woods, there was no median, just a 5 foot high concrete divider between northbound and southbound lanes. As I watched in horror, a deer came out of the woods on my right, made it across all the southbound lanes, LEAPT over the concrete barrier into heavy traffic going north. I was beyond it at that point, I can only imagine it landing ON someone's car or just in front with the driver having no warning or chance to stop.