The MLG Pillow is a buyable pillow from the PFS store/pillows section. The Pillow is short for Major League Gaming Pillow. It has a MLG skin on the pillow, with various relateable items as particles.
Sometimes, playing with a computer or a phone wasn't enough for some people. I mean, some would be the best gamer, yet, secretly miss real life.
So, some fanatic company thought this was a good well damned idea. They could cash in the dead meme that nobody uses anymore, while using up a ton of other dead memes because they were unprofitable to be sold on their own.
Apparently, they sold so well, even the stores couldn't cope with demands. Just don't expect your child sleeping on a pillow making ear rape sounds.