Life in Hell: Bongo pledges allegiance to Frank Zappa.

My dad had this up on his fridge for years, and I stuck a copy on the door of my dorm room in college. It ran a couple weeks after Zappa passed.

Groening, of course, famously said "Frank is my Elvis."

(Sorry for the lack of attribution on the scan -- which is much more legible than any other copy I've found online -- but this really is the copy I printed and put on my door about a decade ago and I have no idea where I originally found it.)