Open Question: ex-friend harassing comments…. what to do?

Im at a car show out the blue he comes up to me. I stick my hand out to shake his. He is like "nah thats ok!" im like wtf then he starts talking all this drama bs about how he has been hearing im talkin about him! Im like w.e man! He says he dont have a problem fighting and he isnt a "regular black guy" whatever that means! i brush it off eventually he leaves... he came up to me again patted me on the back and said "im everywhere, remember that"! i was like ok man! Another time when i went to go get my car to race he yelled across the grandstand "where you going boy, come back" several times! i didnt say anything! my girlfriend yelled at him though sayin he should shut up he said for he to get me back over there to fight! Finally the last time he said something was when he was leaving he ran his mouth and said "u can relaxe now im leaving" He wants to fight i GUess, i tried explaning to him that i dont talk about him! i could care less, to me he just wants attention! We stopped being friends over a year and half. Only seen him 2 times before today(only said hey before) was civilized unlike today! I DONT like him and DONT want him as a friend! Him and I share a couple friends thats all.