A hammer. This has happened before. My husband is always fast asleep and I don't want to have to wake him up to take out a crackhead.
We both love the hammer, I noticed this as soon as we started dating, any problems and we both seemed to gravitate towards the hammer. We had a utility hammer left in a drawer and one in the bedroom for bad neighborhood control. It's kind of an unspoken preference in our household.
This also happened at my last job, it was night in an unsavory neighborhood, a side door was left open, and someone whistled to see if anyone was there. After they asked repeatedly if I was alone they left. I had no hammer but they could tell by the look in my eyes that I was not afraid and might just take their head off. I am a tiny female, but I can scare the hell out of a lot of people when they are trying to create a problem. In which case, I grabbed an attitude and resourceful thinking. I didn't even bother with the phone...Just scared the asshole away.
Sidenote:
None of that applies if what you are looking at is not human looking, or the coyote you were expecting to see.....I call it "not a coyote" in which case you just lock your door and hope that it leaves and try to get a photo of it. There, you grab a camera and take a photo of it as best as you can.