HappyTale is what remains of Error!Sans's AU after he destroyed it. Eventually, CORE!Frisk managed to slightly restore it to it's former state and Ink!Sans restored life to it. Error!Sans eventually found this AU while it was being restored, and attacked it. During the battle, the AU disappeared, and was never found by either Ink!Sans or Error!Sans again. It now resides in the Rho Exclusion Zone, as Rhosaith had captured the AU during the battle. Inside the REZ, it was safe from all Protector and Destroyer activity, though due to the extreme circumstances Rhosaith found the Universe in, major errors and the like have happened, and the Universe is now like a world of nightmares, as the inhabitants have dramatically changed, for the worse.
- The name of this Universe, as you can probably guess, is a misnomer.