Someone who thinks they know everything about every current news story and who tries to give creative and interesting angles within conversations about them but actually comes out with self-concocted, total irrelevant shit that shows them up to be lacking in knowledge and hugely uninteresting.
"I'm sick of Steve coming out with total crap all the time. He thinks he knows everything and can't help but speak, even if he knows nothing about what we're discussing."
"Yeah, he's a real shitdoctor."
"True. I've had enough of his shit."