Name something Twilight Sparkle is afraid of

[Windy Breeze 15,175]

Twilight Sparkle is afraid seeing a book fell off the bookshelf (Oh, and if you did it on purpose, good luck living as a cactus)

[Olly 1,008]

God-king Xerxes

[TigerGeekGuy 4,659]

Twilight Sparkle is afraid of a giant ladybug monster with eyes where the spots should be and bleeds hot cheese.

No wait, that's just her nightmare. She's really afraid of losing everypony she cares about and failing not only herself, her friends, and her mentor, but all of Equestria.

[Octavia Heartstrings 28,406]

Silverfish.

They'd eat all her books, wouldn't they?

[Windy Breeze 15,175]

Maybe... I never heard of them

[CheeryFox 23,811]

Dusty books and SpaghettiOs. 

[Angle Alastor 3,805]

ladybugs obviously lol XD

[Patty Thundersnow 4,129]

Quesadillas that are too cheesy.

[Sparklefan1234 161,850]

Overdue library books.