Anti-brony
Someone who dedicates their internet life to hating fans of the Hub television show "My Little Pony: Friendship is Magic."
These "anti-bronies" tend to try and put bronies/pegasisters down by using the most overused insults that the Internet had to offer, and also making false claims that are not backed up by evidence.

Basically, they are just another Internet troll group that shouldn't be taken seriously.
Anti-brony: OMG U BRONYS R SO GEY

Brony: Oh look, another dumbass.
Anti-brony: WUT U CALL ME BITCH IM A SNIPER IN THE NAVY SEALS ILL SNIPE U AND KILL ALL OF U FEGITS
Brony: You say that over the Internet, but you don't have the balls to say it in real life.