The half-eaten corpse propped against the wall was reason enough to run. A terrifying howl of anger bellowing from the alley behind him clinched it. He wasn’t planning to wait around and become a meal(.)Good, I'd end it here though and get rid of: like the dead guy.
Evan ran.
Wherever he turned, it chased him, taunted him, and closed all possible routes of escape. He ran from something that he had not seen, just heard, but knew enough not to wait for what torment awaited him.
IMO 'it' won't worry or scare me and this paragraph is too vague. Give me a hint. Demon, beast, shapeless evil? Give me something, even if I know he's not sure of what 'it' is. I'd rather you show me how he ran, where, what happened and how 'it' blocked and taunted him. Was it an imagined darkness, a suffocation only felt but not seen that had him searching for an escape. Was it a beast or a supernatural predator? What?
Don't get me wrong. This interests me, if your writing didn't interest me, I wouldn't care what 'it' was that seemed to be hunting him. I'm intrigued. I'm interested, now captivate me, throw me in this horror, trap in the the experience.
You are most definitely on the right track. Thank you for sharing your work! Best wishes.