Mare doesn’t even have enough screen time to have anything to insult. Heck, she doesn’t even have a canon equestria girls counterpart, has less then 3000 images despite being around since season one, had had less then a paragraph of dialogue throughout the entire series, isn’t even a popular background character unlike the other ones, and the only thing I honestly remember about her is she dyes her hair.  
To quote Deadpool in the rap battle “I don’t even know enough about you to diss you”.

Is this legit? I’d really like to see it!

@Trilby Pony  
Prepare yourselves, lyrics are coming.

@Hiddenmac  
and Nopony messes with Mayor Ma

West, I lova ya, but you’re so much better than Family Guy in every sense of the word.