I suggest checking out The Many Deaths Of Rainbow Dash

I love the scene where pinkie is using Rainbow's guts as a tire swing lol

It's actually pretty good (and no, pinkie is not insane-murderer. This time.)

and even though it's a gorefic it's hilarious

Cheerilee garden isn't good enough for me lol

If you like gore fics, I strongly recommend Cheerilee's Garden (along with the two chapters after it, the Scarlet Harvest ones). It might make you sick, though. It's a pretty intense story.