Rainbow Dash has a prophetic dream about chickadees. It's all rather stupid though. A 50 minute story. Also, Gallifreyan technology and prime numbers and dumb jokes appear. Story 4 of Doubleshotober.
Pinkie's Cocaine dealer is an anthropomorphic cat named Thrilla Vanilla. Things don't go too well for him. A cursory discussion of Equestrian drug culture and policy also occurs. And also interspecies breeding.
Trash Doves invade Ponyville, Twilight Sparkle is annoyed, Fluttershy is ambivalent, and everyone learns the slightly depressing yet also uplifting philosophy behind Pinkie Pie's party proclivities