At Dragon Con 2013, comedian Greg Benson of Mediocre Films walked around the conference while going up to and hitting cosplayers in the face with his microphone. The cosplayers all thought that they were going to participate in a friendly Q&A session, but Greg thumped that idea out of their masked heads very quickly. Previously, we wrote about Greg and his similar prank where he hit famous YouTube stars in the face with his microphone at VidCon 2013.
Here is a bonus video where Greg hits even more unsuspecting cosplayers with his microphone: