Groening once figured that the 31st century of “Futurama” would be a classist society, and that people would be categorized into numbered groups from one to nine. He said:
“The original idea was that there was a caste system in the future and people were known by their numbers. There were different levels and mutants and sub mutants — which we ended up getting around to — but we sort of dropped the idea of gown-wearing zombie slaves.”
“Gown-wearing zombie slaves” sounds like a workable story element that might be used in a more recent, single episode of “Futurama,” but one has to admit that it would perhaps be a little too high-concept to include in the 1999 pilot. It seems that the designs were drawn, and the showrunners included him in background shots of eleven episodes, just to fill out the space.
Eventually, Number Nine was used often enough to be included in an actual story. In “Into the Wild Green Yonder,” Number Nine introduced himself as the leader of the Legion of Mad Fellows, a loose-knit group of crazed drifters who wear tinfoil hats and scream at invisible voices. In that film, it was revealed that tinfoil-hat-wearing weirdos are actually blocking out psychic signals from everyone around them. Among the voices are a malevolent species of invisible monsters called the Dark Ones who aimed to remove life force from the universe. For “Futurama,” it was all very abstract. Number Nine Man was one of the many “Futurama” characters voiced by David Herman.
And why did Groening choose the number nine? It seems it was merely because he was a Beatles fan.