Log 1:

Pinkamena "Pinkie" Diane Pie was a normal happy peppy pony who lived in Ponyville, but one day, when her pet gator Gummy unexpectedly passed, she became delirious with grief and made Gummy into a cupcake to honor him, but when she ate the Gummy cake she realized that anything... or rather, anyPONY could become a cupcake.

Log 2: Pinkie had ditched her nickname in favor of her real name and began making pony cupcakes with a detailed numbering system to go along with it, but was caught and sent to the Ponyville Mental Institution following an attempted killing of a filly named Scootaloo. Scootaloo survived and was returned to her aunts Lofty and Holiday. 

Log 3: Pinkamena would escape the institution and adopt a mangy rat she named Frothy, she kidnapped Ponyville resident and Cloudsdale known celebrity, Rainbow Dash.

Rainbow Dash was found dead in the basement of the Sugarcube Corner bakery, but Pinkamena was gone...

More is still being documented about this case, more will be added soon...

Will write back, Princess Twilight Sparkle

Below is a picture of Pinkamena as far as we know currently