Lurken
The Lurken are a mysterious people who reside within the underground of the Overworld. They are a variation of the Ancient Builders. Because they thrived beneath the world, they survived the Great Reboot that removed the rest of the Ancient Builders from the server. They survived all the way until the era of David the Hero of Legacy, where they left behind ancient structures underground. It is believed that after the Great Reboot, they were the ones to teach the new generation of humanity how to utilize redstone.
Culture
Average technological level
The Lurken were master redstone engineers. They had also possessed access to the Nether through Nether portals, which they utilized to harvest ingredients for redstone circuitry for their creations.
One theory regarding the fall of the Lurken is that with their redstone prowess, they were able to create a Command Block. Due to improper use, they accidentally created a plague that wiped out their cities.
Although the addition of the Ancient Cities from the Caves and Cliffs update may suggest that the Lurken came to exist as a result of the update, this is not true. The Lurken within Notch's server of Minecraftia have existed for several centuries, and is even a point of influence for the Mojang staff in-universe to introduce the Ancient Cities.
This is just an idea, but with 'The Wild' update, I wonder if this may give you some more fodder. For instance, how did the Warden come to be, and is he a product of the Lurken inhabiting the cave systems? Also, was the Warden created as a form of security like the Iron Golem was for the villagers? At least, that's what comes to my mind.
The theory potential that recent updates have added with the Deep Dark biome, the ancient cities, and the Warden definitely have been making my worldbuilding mind go off. There's so much storytelling potential with all of those.
Agreed. My kiddos have been tearing apart the game, exploring the Deep Dark biome to incorporate it into their storytelling. My son (he's 5) draws pictures, and his idea was the Warden was left alone in the dark because the people got sucked into the end and eaten by the dragon. And that's why the Warden is listening, trying to find his friends again.
That's actually really adorable. Do you mind if I use that idea at some point in my story, say, a random child says to the main character that about what they think of the Warden?
I'm sure my son won't mind. :) Honestly, I get many ideas from the stuff my kids draw.