Vocals used by death metal/ hardcore metal vocalists. It started being called this because the voice sounded like the cookie monster. In album reviews people will often cite the cookie monster growl. Also see Bree for another example of a death metal vocal term.
The vocalist of (band) switches between high pitch metal screams and a low cookie monster growl.
Something that started on iTunes music reviews, somebody would put the words "Click yes if you agree!" into thier review. It was kind of strange because there was no "yes" button. The term is growing... and i have seen it a couple other places than iTunes. I originally found it in some random review a couple of years ago and like a year and a half later it came out of nowhere.
This band is so awesome!!!!!!!11
Click Yes if you agree!