What would the MLP and RS characters dress up as?

Just one more week until Halloween. Or for all you bronies out there, Nightmare Night.

Wanted to just ask a cute little question: what would your favorite characters from both My Little Pony and Regular Show dress up as?

And FYI, something better than Starswirl the Bearded.

Let's imagine, guys! After all, if I can dress up as MU Mike Wazowski, what can cartoons like Mordecai or even Fluttershy (if she has the nerve to even get out of her house during this holiday) will dress up as?

After watching the Book of Life, I believe and don't believe Xibalba could be Discord.