Bullying is being taken VERY seriously by today's school administrators.
There are kids who have killed themselves, whether it was in school, and in at least one case over the Internet.
These deaths are tragedies, and did not have to happen.
Will you incur some type of backlash for reporting the bullies behavior?
Maybe so, but if he does, REPORT HIM AGAIN, be sure to have at least one witness who is not biased, and it will be the second count of him being an asshole ON RECORD, and he will likely be suspended or expelled.
Bullies are cowards.
I used to beat up bullies in school.
My Father would get calls from the principal of my school every year and ttell him what happened, and my Dad would say "If your staff were doing their jobs my son wouldn't have to do it for them."
Student vigilantism is not very well tolerated in this day and age though.
So, before this asshole gets too bold and really physically damages you, report his sorry ass.
When I was in seventh grade there was this one eight grader who was a real fucktard.
During the first week of school he would "book" me (slap my books out of my arm).
I got sick of it by the second day.
He fucking had to be following me around because it was in three different places in two days.
Then on Wednesday, I saw him walking toward me at the end of a long hallway.
I walked right toward him.
When I was almost in range for him to book me, I dropped my books and immediately punched him in the balls as hard as I could.
He dropped to the floor in agony, and I said "Don't book me again, motherfucker."
That was that.
I was lucky.
Many times bullies will back off if you fight back, even if you don't kick their ass, simply because they respect you for not being a sissy.
But there is no guarantee that this wil be the case with your special fucktard, so play it safe, don't sink to his level, and drop the dime on this piece of shit.