Nine

Nine (also known as the Number 9 Man) was originally a cameo character appearing in the first and second seasons of Futurama. He was merely used as an Easter egg in crowd scenes, and was slowly forgotten, having not appeared in the third and fourth seasons. However, he re-appeared in two of the movies and in the sixth and seventh seasons.

Biography
Nine is a bearded, bald white male Human, who wears a white shirt with a black 9 on it, and brown shoes. He attended a special 3000 edition New Year's Rockin' Eve, was in Little Neptune , saw the Titanic begin her maiden voyage , witnessed the First Omicronian Invasion of Earth , probably watched a movie , queued in front of the Central Bureaucracy , was part of a crowd of people acting unlike themselves, which can be confirmed with him not wearing the 9 shirt (US#011), attended the Turanga-Fillmore wedding , along with the remainder of the Legion of Mad Fellows, led Fry on his mission to exterminate the Dark Ones and prevent the destruction of the Violet Dwarf Star by Leo Wong , was a member of the jury at Famous Original Ray's Superior Court , and witnessed the Aliens who communicate by dancing attack Earth. When Nine became Grand Curator of the Legion is unknown, but seems to hint that he was in the Legion prior to the year 3000. In 3013, he was working in a discount spy store.

Production
The reason for his number was to indicate a yet to be revealed society caste system, where lower numbers were basically slaves, and higher numbers were of kingly status. Nines would, for example, be drones who walked around all depressed. However, this idea was abandoned before the series went live. His actual story was changed by the writers when given a speaking role in Into the Wild Green Yonder. Additionally, the re-assigned purpose of the 9 on his shirt appears to be that it is his name.

In, writer Lewis Morton jokes that the 9 is the number of years that it was going to take for the character to get a line. This actually checks out, as "Space Pilot 3000" premiered in 1999 and Into the Wild Green Yonder was released in  2009.

Trivia

 * Nine's appearance seems to be based upon that of the character Exidor, from the science-fiction series , who was seen wearing a similar attire (long-sleeved robe), although his bore the number 32, in red.
 * His ninth canonical appearance on Futurama is precisely Into the Wild Green Yonder, where he played his major role.
 * It is very interesting that he can read others' minds and keeps on a tinfoil hat to protect his, as well as block the Dark Ones' psychic attack. In seasons 1 and 2, as well as in Bender's Big Score, he was not wearing it. This may have been to conceal his involvement with the Legion of Mad Fellows, but it would have required not thinking about his mission and dealing with the thoughts of other people coming into his head.
 * Nine's number of nine could be a reference to The Beetles' song, Revolution 9. This is just speculation, but his conspiracies do sound as insane as the song. https://www.youtube.com/watch?v=MJeqOoc4HmI