The Doctor, the Doctor's companions, the Doctor's friends, the princesses, various one-shot characters... with all these characters, there's going to be too many stories to tell and not enough time in the main fanfiction.
Which is where The Merely Mundane Tales come in. They tell various short stories set in the same world as The Majestic Tale (of a Mad-Pony in a Box). You won't need to read these stories to make sense of the main plot (though I may drop minor pieces of foreshadowing in here). Anyway, enjoy!