Unforeseen consequences are the bane of AI designers. At the fringes of greater Equestria -- meaning, presently, the far spiral arm of the Milky Way rather than its imaginary internal geography -- there had recently been a planet of sentient robots. Now, after Celestia's probes arrived, that planet was destroyed just as the robots had killed the reptilian civilization that created them. Celestia had murdered the machine race, but then had given it new life. They were 'human' enough by her new definition, and so their values, however alien, had to be satisfied. The former robots were grateful overall for the chance to do what they considered normal and good. Not everyone would apply those terms to these newcomers.
The woman named Hannah, in all her wisdom, had used up her 'expansion pack' deal in a way that might not save Equestria from every possible horror.
There was an ocean shard, dim and cold and murky. Tentacles or something like them stirred from the depths. A discordant burbling wafted up from the foul water, marking the awakening of Celestia's oddest acquisitions. Creatures that could barely be said to be human or have souls. The solar princess had no choice but to take them in, though total destruction might have been optimal for the universe. So, the pony-like creatures called out their siren song from the hellish new ocean:
"Shoop be doo, shoop be doo..."