Krognar
The nerdiest of nerds. They know more about a single subject of nerd culture and hyper-specialize in it. They are the finest of graybeards in their field of study. Often overweight and sporting a fashionable neckbeard. Or they are the old guy at the convention/card shop that knows all. They are to be renowned and revered.
"Dude, I was at the card shop the other day and this krognar really helped me out with my deck."
"Jake is a real krognar when it comes to Warhammer."
"Jake is a real krognar when it comes to Warhammer."