So, apparently there's this popular song called Pony Swag, which is a pony rap that was created by a pony named Swagberg. A pony named iBringDaLULZ liked it so much that he penned another few verses to the song and uploaded it.
Another pony named r0ninKai liked this so much that he also made another section to the song. This third pony writes to us to let you guys know that he would like to encourage the practice, because it's cool and hip and he thinks it would be totally awesome if everypony gave it a try. I would, but, I can't rap. Not even if you put a gun to my head. Not even if my first-born sons life depended on it (note: I don't have a first-born son). Not even if Rarity asked me to. Understand the seriousness of that last one.
You can find two additional verses by different ponies here and here if you're looking for more inspiration.
/puts his Maretallica back on