This is inspiring. Why? Because dude! That guy is having fun! When was the last time you had fun? You might look at him and say, ick, it's a homeless guy, but he's not just homeless. He's awesome!
So say what you want about him. He was inspired -or mentally ill- enough to grab some tree branches, hide behind them -in plain sight- and "Girrraaah" at people for his own entertainment. What the majority of people are missing in their lives are inspiration and the conviction that they are doing something good, that might change the lives of others around them.
I challenge you to find something moves you. Something that inspires you to do something you normally wouldn't do. To get up and scream "Girrraaah" at random people just for your own entertainment. Hopefully you will record it and send it me. ::))
Get out there, Do it. Do it well. Just do it.