I would get your Mom to call. How badly is he wounded? Do you know exactly where to find him? Can you give accurate details as to why he is a nuisance? I'm not sure hissing is enough
And do you know this man's address? Do you know of other people on your street (or that have seen him) that can back you up?
The reason I would get to to ask your Mom is only that I am worried that Animal Control may not take you as seriously as an adult. I mean nothing bad to you by saying that.
The other questions are ones that Animal Control are probably going to ask. The more info you have the better.
If your Mom won't do it go ahead and call. I know you are worried about this poor guy and your pets as well. Regardless of what happens, and you have to be prepared for this, even if he is put down, you saved him a lot of pain. He will know that somehow whether across RB or in a new families home.
You will be doing the right thing if you call. He won't be any worse of than he is and will put your mind at ease~