Why is she scared?
Clopfics [noun] Clo-pfics. definition : If Brony sees something about it, they get on the computer and starts mau5turbating about Ponies 2. Also jacking off to them.
Poor little Applebloom xD She's too young to see such things!
This was probably her reaction to those dead ponies in "Story of the Blanks". Loved that game...
What made her scare?
She saw Big Mac's internet search history.
he's been surfing titty websites.
...judging by the context, i'd have to guess...clopfics?