Packs of deer rove around my new neighborhood, and they have no fear of people or dogs. Unfortunately, my dog wants to chase them, and she doesn't seem aware that they're bigger than her.
A few times, I've encountered does and fawns. The does get protective and act as if they're going to charge at my dog, pawing the ground and grunting. The fawns frolick and try to get my dog to chase them. I have to drag her away. I've also seen stags with antlers, but they tend to be solitary and not as confrontational.
Here's Saphira relaxing in her guard dog pose. She likes to hang out on the patio or near doorways, facing outward to ward off the forces of evil.