Fluttershy mentions that Twilight has been turning ponies into sandwiches. The same poison is in Twilight.
Pinkiepie looks shocked. "How do we help her Flutters?" Fluttershy smiles. "rarity might be able to do the spell. With Luna and....."Twilight captures Flutters and prepares to make another sandwich. She laughs as she cuts piece after piece off of flutters. All that was left was the skeleton of what was once the cutest pony.