How do I get this kid to leave me alone?

Im in year 8 and I'm 13, and this boy in the year below me is like 11 or 12. Me and my friend were sat on the bag racks at school and he kept grinning and me then came over and sat right next to me and was like 'Alright babe?' I completely blanked him cos he came over as proper y and arrogant. And earlier today I needed to go through some double doors at school and he was holding them shut, so I said 'Scuse'. and he was like 'Nah' so I said 'Dude. Move it.' and he said 'Aw alright I'll let you through'. And then I was walking through the corridor at school and he was walking the opposite way (the corridors are reeally tiny at my school) and he was coming straight at me, then at the last minute he ducked and moved out of the way. He's really short and y and arrogant. How can I get him to leave me alone?