I'm making a video explaining what we know so far about the Slendytubbies timeline, and I realized something I hadn't noticed before: In the Slendytubbies 3 Cave notes, it says that the three tubbies (the Maze Tubbie, the Yeti Tubbie, and the Cave Tubbie) were test subjects in painful experiments, but then they got infected. How can that be if there's a huge distance between the infection and humans?
Kinda sounds like a plot hole that Sean didn't realize when making this side-lore, I assume he only made it just to add like a form of suspense to the player. But I'll try and make a theory about it anyway:
Tinky Winky wasn't actually the TRUE patient zero for the virus, but actually these 3 patient zeroS that he heard were being tested on somewhere in the caves by the mere last of humanity. The humans had these 3 test chambers for their newly created species, the first (and largest one of course) 4 test subjects in the main land, built to test out how well they could survive within the world itself, especially how they get along and just overall basic life essentials. The second chamber being 3 test subjects hidden in the cave of the main land, built to test how well their endurance and survival instincts were and their response to negative emotion and environment, hence the very harsh and troubling and abusive experiments by the humans, as well as the dark and scary setting of the cave itself. And the third one, is actually the guardian himself! With the hidden secret lair ordered to him to keep watch of the main 4 up at the main land. This chamber was built to test how well these creatures are at following strict orders and working. One day, Noo Noo saw the hidden potential in these creatures, and how they were being held back by from their "true glory". So, he decided to create a virus that turned them into terrifying mutational monsters. He decided to test do this first test of the 3 test subjects in the cave, being as it is within a very private place, away from the public view. He concocted a very strong hitting mix of the virus, snuck into the cave while the guardian was on his temporary 1 hour break, and slipped the mix into the pre-prepared lunch of tubby custard when no one was looking, and made it back just in time before the guardian's break ended. Noo Noo, watching from his digital camera view as he had also gained access to the hidden wall cameras while he was there, saw them mutate worse and worse with each day. And once they reached "true glory", they went on an immense killing spere on every single human that tortured them, and nobody knew. Noo Noo was pleased with what he had created, and he knew it must go on. So he branched, infecting the teletubby creation machines, making these armless furless versions of teletubbies. And now, it was time to finish off by infecting the entire country's worth of custard by slipping it into the pool at the custard facility where all of it was made. Finally getting into the custard machine at the dome house of the main land.
Whoops, I accidentally wrote a short story book novel.