Derpy Whooves 
"[@MoonGazer Lunarium":](/images/2076993#comment_8447075
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Again, this is probably Rule #6, but it shoots projectiles, so that fits the definition of "gun". As for its classification beyond that, we know she can shoot ponies in the face or butt with it, so if it were classified by any of the laws I'm aware of it's probably more of an airsoft rifle or T-Shirt canon. But at the same time she used it as an offensive weapon during the invasion of the Changelings, so it probably would have to be classified under "Magic Weapons That Do Whatever is Most Funny At The Time And Only Hurts Those Who Are A Danger To Canterlot Otherwise It's Just Really Annoying".
I find it more interesting to wonder where she got the idea of it. I mean, it's the only thing of its kind in the show. So where did Pinkie get the idea?
Super-Extra-Rule-6-Tangent: At Minicon one year we handed out sticky labels and labels on strings that said; "THIS OBJECT IS IN VIOLATION OF MINICON WEAPONS POLICY" for people to tie to or stick on lights, penises, stick on butts, and to cover their mouths with, because Minicon issued a new "Weapons Policy" that forbid any device or mechanism that "projected anything". It was funny, but only from one perspective. They ended up on anything that emitted photons or water or even air, like TVs and faucets and fans and hot air ducts. The hotel was not pleased, but the next year that policy had been "amended". Good times.
Looking For My Doctor
Again, this is probably Rule #6, but it shoots projectiles, so that fits the definition of "gun". As for its classification beyond that, we know she can shoot ponies in the face or butt with it, so if it were classified by any of the laws I'm aware of it's probably more of an airsoft rifle or T-Shirt canon. But at the same time she used it as an offensive weapon during the invasion of the Changelings, so it probably would have to be classified under "Magic Weapons That Do Whatever is Most Funny At The Time And Only Hurts Those Who Are A Danger To Canterlot Otherwise It's Just Really Annoying".
I find it more interesting to wonder where she got the idea of it. I mean, it's the only thing of its kind in the show. So where did Pinkie get the idea?
Super-Extra-Rule-6-Tangent: At Minicon one year we handed out sticky labels and labels on strings that said; "THIS OBJECT IS IN VIOLATION OF MINICON WEAPONS POLICY" for people to tie to or stick on lights, penises, stick on butts, and to cover their mouths with, because Minicon issued a new "Weapons Policy" that forbid any device or mechanism that "projected anything". It was funny, but only from one perspective. They ended up on anything that emitted photons or water or even air, like TVs and faucets and fans and hot air ducts. The hotel was not pleased, but the next year that policy had been "amended". Good times.