Pinkie Pie lost those she hold most dear in her heart once Sugar Cube Corner got destroyed, in the process half of her body got burned. Having witnessed the death of the Cake family marked her forever, slowly losing her sanity as time went on.
 
No other pony knows Ponyville as Pinkie Pie does. Every street, every corner, every inch of the town is marked in Pinkie’s brain, making it the best battlefield for her. With this in mind, after the failed “Operation [REDACTED]”, she decided to adopt the arts of urban combat and locomotion to become one with almost every urban environment in Equestria.
 
After Pinkie and Rainbow Dash formed the Sol Invictus unit, she became a master of knife fighting under the wing of the later. With the help of Applejack, she combined a grenade launcher and a shotgun to form a revisited version of her “party cannon”.
 
With these weapons and abilities Pinkie Pie holds patrol in most of the key towns and cities across Equestria.  
All those who wander into her hunting ground will be haunted by THE LAUGH, more than the Element of Harmony she represents, she gained the nickname because that’s the last thing you will hear before she strikes.