The top of the food chain in the respective industry, company, group, etc. Usually highly regarded and often unjustly intimidating or feared. The head hauncho runs shit.
Summer of 72 - Somewhere in Europe
Bob Weir: yo do you want to split this ten strip with me?
Phil Lesh: No i’m good, i took a tab in amsterdam and Head Hauncho Jerry told me i freaked him out with that mask i wore
Bob Weir: You’re such a bitch, Phil