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Both the Futurama fan community and even the writers for the show will use the wiki The Infosphere
as their one-stop Futurama factoid site. There is an article on the wiki that addresses "the other"
Like the article states, there has been absolutely no references
to the legend of "The Other". While it was quite the hot topic for many fanfictions back in the day, the single idea has since faded away from the minds of current Futurama fans (or nerdlingers, I guess there really isn't a particular title to us like Whovians or Bronies). I don't think it has been brought up to the staff nor has the staff referenced it. Maybe this upcoming season the show will address "The Other", as the executive producers of Futurama have both mentioned this upcoming production season will feature a strong Fry/Leela romance arc (well, the close of it).
If you're interested in discussing this topic more, there's loads of fans who crave potentially-romantic speculation in the Shipping thread
in the Human Resources Department
While I would say it is almost-definitely implying a romantic relationship between the Mighty One (Fry) and the Other, there is still reason to have doubt. In the article I posted earlier in the post on The Infosphere, it does mention that the concept of "The Other" may have been inspired by the Star Wars Trilogy's Luke and Leia's relationship. Years ago, somebody made the argument that the possibility is still open that they could be siblings, considering their similar hairstyles (there's an image juxtaposing the two somewhere in the metasphere...). However ridiculous despite their age differences, they could
related, I guess. Futurama is notorious for dropping lines that may come true in future episodes. For example, in an early episode, Professor Farnsworth rambles on about how he will create super-atomic super-men as he is exiting the room, to only later develop super-men for the Globetrotters basketball game in "Time Keeps on Slippin'". I also believe Inez Wong once complained that Amy isn't getting any younger. Then when Amy was youthicized in "Teenage Mutant Leela's Hurdles", Inez began to complain that this isn't some universe where she's getting any older. Well, if it counts for anything, we did see a somewhat-alternate (depends on how you define it) where Amy was significantly older. In the case of "The Other" relative crack-theory, Fry did theorize in "Bender's Big Score" that Leela and Lars (alternate universe Fry couldn't marry) because they were cousins. While the line seems fairly expected humor, I would like to note that the line remained unchanged since the first script, which featured many changes to many one-liners.