Demon Dog

Demon Dog is a screamer video made by Dane Boedigheimer (YouTube user Daneboe), first uploaded in 2009. The video begins with footage of Dane's dog, Charlie, looking around the room, along with a header reading "Charlie Can Make An Angry Face". Offscreen, Dane himself (who's recording) is trying to encourage Charlie to make the angry face. It takes a few attempts, but after Dane says "Come on, make the angry face. Angry!!", Charlie's face becomes demonic and he lets out a loud roar, before turning back to normal. Dane then rubs his head, happy that he pulled it off.

Link
NOTE : The following video contains a screamer!
 * youtube.com/watch?v=stnoShFlFiM