A Crunch
A Crunch is when someone’s personality is so loud and obnoxious, it turns your whole group into a bunch of tired, confused zombies.
"My friend is a Crunch. Every time she speaks, I feel my brain shrinking."
He’s such a Crunch, I had to take a nap after talking to him.
That girl is a total Crunch. She’s like a scream in a classroom.