You should try the Abuelo Macho Burrito from the Mi Pueblo Taqueria in Novato, CA. About the size of 4-5 full size burritos, the menu says that if you can finish it, it's free! Given the size of one normal burrito at Mi Pueblo Taqueria, I can't even imagine what the Abuelo is like....

I think it'd be right up your alley, man.