An expert in some specialist field that is usually consulted in irregular brief meetings, traditionally over a cup of coffee. They vary from incredibly useful and valuable to heartbreakingly incompetent.
Often occur as management pets, and are most frequently spotted around pending disasters.
"Damn, we can't route this cabling without moving that duct."
"Can we do that?"
"I don't know. Another one for the coffee expert?"
"Yep, I'll set it up."