pyrotechnical cheez potato
A person that, rather being a couch potato, is a modem potato, spending long periods of time surfing the web, obsessing over exceedingly silly (aka "cheesy") information, to a such a degree that they spontaneously self-combust, but survive in a new form.
John used to hang out and go to parties, but after he became a pyrotechnical cheez potato, we didn't see much of him outside his computer room.