I have a problem with a friend!!?

Hey yahoo, i need help people ..ok so i know this kid at my school who is a total social reject. Nobody likes him basically because he is a very weird and somewhat annoying kid ..he is always talking about weaponry from the Call Of Duty games and he basically has anything there is to know about guns in his mind ..you can basically think of any random weapon and he will tell you different facts about it ...anyways he tends to talk about video games alot too he asks everyone if they have a "steam account" or 'Xbox live" and he smells bad and when i asked him why he smelled like mustard the other day, he told me because he only takes 1 shower every week. and he always wears combat boots to school and he dresses awkardly like he wears really tight shirts with really baggy stained cargo pants .... he is also a very stubby short kid of about 4,11 and he always looks like he hasnt been out of the house in a few days ,probably because he spends most of his time on his computer or on video games ....people at school make fun of him alot too ...all the guys call him "chick kryptonite" because all the girls leave when he walks by... I feel truely sorry for him ..because his dad is dead and his mom abandoned him for a life of drugs ...and he lives with his uncle ..... and i actually care about him ..... sometimes at school i say hi to him and people tell me "don't talk to him ...he's weird" and just the other day some of the popular kids threw a water balloon at him and i could see the sadness and humiliation in his eyes all the girl were laughing and no one asked him if he was alright ...so i finally did and he smiled and said "yeah ,i am" ..i thought he was a brave mother f**ck*er after that .....so i wanted to know .. how can i help him have a better life? or atleast better treatment at school.. please help me because i do feel very much sorrow for him.