What do you call people that insult other people?

People that insult other people you call well ... bullies people that insult other people sometimes are jealous of the people they are slagging and sometimes its just plain nasty or maybe they have a hard life or something !! i have been insulted many times in fact so many times i just laugh because i cant help who i am i have red hair and for some big reason that's such a massive deal !!!!!!!! but i like my red hair I'm 18 now and i have been slagged for it even since i was well ever since i started primary school people are SO nasty and people that slag you are better being avoided.