Emmy

Emmy is a digital being and the main villain of the Goosebumps Hall of Horrors book, Don't Scream! 

General Information
Emmy has a voice and a brain, but she got no body, but in case anyone sees it on a screen, you will just see her mouth.

She can possess any electronic instrument to comunicate with people, zap them, and she can even melt the electronics she's in.

History
Emmy appears for the first time in a cellphone Jack finds in the bus. When Jack raises the phone to his ear, he ears Emmy's voice saying:

"Hi, Jack. Don't scream. I've been waiting for you. I'm your new friend."

Jack ignores the voice, thinking it's a joke, but when he ends the "call", Emmy keeps talking.

"Don't make me angry, Jack. I'm warning you."

Then Emmy makes Jack do some horrible things, like stealing a computer from his school.