Every fandom has a list of insults like:
PERCY JACKSON: You stupid little demon/mortal
HARRY POTTER: Good for nothing muggle/squib
DIVERGENT: You stiff
HUNGER GAMES: You're as useless as PEETA! Whatcha gonna do about it? Turn into a rock? Bake some bread?
MORTAL INSTRUMENTS: You foolish mundane!
AVATAR: As pathetic as the cabbage merchant!
CITY OF EMBER: As fat and as selfish as the mayor!
These are just a few, and there are more to come, so feel free to comment down some of yours!