Ok, so I need some advice....?

I have a son that is 2 years old. His father has seen him only twice in the past two years and never given me any money or anything. He never calls or anything. Well, out of the blue he calls and says he is taking me to court. This guy is a really bad person. I do not want him to have any rights to my child. I mean, he choked me and pushed me while i was pregnant. He has a criminal background that includes drugs, alcohol, and other things. Also, a few days after I had my son he showed up at my house unannounced and was drunk. We got into a really bad fight and I called 911. The cops came out and he got arrested for underage consumption at my home. Has anyone been through this? What are the chances that he will get visitation rights?