In my review Assassination Classroom, I happen to also be at Fanime when Cthulhu attacks. Some of you may be in this since a lot of cosplayers at Fanime appear in it.
The attack part starts at the 6:17 mark. Plus the show intro done by voice actor Kyle Hebert. ^.^https://www.youtube.com/watch?v=5NwMpw5jUR0