Happened to me before several times. I took one in that I witnessed get dumped at the corner and they hauled ass, and he waddled over to me putting up my Christmas lights. Very sad but he proceeded to give me the best ten years of loyalty and friendship before he passed. I watched him grow and become the best well-behaved pet ever. I never regretted taking him in.
I've been giving cat treats and water to a half-wild tabby for the past four years and he 'guards' my house while I'm at work. Sometimes leaves me a dead bird or lizard as a thank you. I have a soft spot for animals.
The animal probably got lost or dumped in your neighborhood by someone who could no longer care for it and is wondering what did it do to be treated like that. It's also very hungry and thirsty. You can call the pound and they'll come pick it up and add it to the list of cats and dogs they already have that no one wants. Eventually it will get euthanized. It's up to you if you decide to feed it. Who knows, maybe he came into your life for a reason. Good luck.