That's a Great Horned Owl that got itself tangled up in some netting. The house where I found it like this backs up to a golf course. The home owner had put up the netting to cut down on stray golf shots careening into the backyard and through their living room windows.
I was able to wrap the bird up in a towel, so I didn't loose a finger while working on it. Both the beak and the talons on these birds can really do a number on you if you aren't careful. A little work with my knife, and I was able to get him down and the netting unwrapped from his foot. Luckily he hadn't been hung up for too long, and aside from a bruised ego he was none the worse for wear.
I took him around to the front yard before letting him go, so he didn't fly right back into the netting.
I learned that lesson the hard way.