SCP-8564: The Costume gun

If you don’t already know the SCP-Foundation, I can only encourage you to visit their website, it is an absolute blast of fun/horrific/wonderful stories created by people around the internet with a common goal: Secure, Contain and Protect humanity from harmful entities!
This article doesn’t exist on their website, but as I wanted to write something related to the topic, I had to do it this way!

SCP-8564: The Costume gun