I know nopony is going to get this, but if at least 1 person does then I'll be happy:
In season 3 episode 10 with Discord, about 15-16 minutes in one of the sound guys made Angel's voice the same as Skillet from 12 oz Mouse. I don't know if it's a homage or a generic sound like the Wilheim Scream, but it made my day either way.
If it was done on purpose, then this show is 20% cooler.