A bear shaped space craft cruised near the planet Earth, days before the invasion. At the time, all it did was orbit the planet, seemingly observing the goings on of the planet, studying its history. The occupants of the ship looked like cyan skinned human toddlers with pointy ears and bulbous antennae, and they did not look at all pleased with what they learned about our planet. On the ship's bridge, sat on the captain's chair and drinking coffee from a sippy cup was a princess. Princess Delly of the planet Pacifier-12.
"Your highness," Lieutenant Jason addressed her, "We have determined that this planet is mostly suitable for us to colonize. Its atmosphere is breathable, its food sources are comparable to our own, it possesses clean water, and its proximity to its sun is perfectly habitable."
"There's still one huge problem with it, Jason," Princess Delly said, resting her cheek on her tiny palm, "Its inhabitants. The dominant species is constantly at conflict with itself. I've seen the reports from the research division, and they say that these 'humans' as they're called have a huge history of civil wars between these arbitrary divisions called 'countries'. It's absolutely terrible is what it is! How could they possibly perfect space travel like we have if they're constantly fighting among themselves?"
"Are you proposing something be done about that, your highness?" Jason asked her.
"Yes absolutely," she nodded, "We're going to go through with my original plan of converting everyone on the planet into toddlers like us. They will all be granted the knowledge and emotional maturity of a 'grown-up' as they call it, but given the mannerisms and speech impediment of a three year old, as well as the diaper reliance of a newborn. Their bodies will be regressed until they've turned three years old, and they're gonna stay like that even as they reach their twilight years."
"Of course, you will have a solution to the 'where babies come from' conundrum this will cause, right?" a bridge technician asked her.
"Well, okay," the princess nodded, "Let's turn 10% of them into immortal mommies whose job it is is to keep the species from dying out. They will be kind and nurturing, and super chubby. They will never die and can't be killed, and they can make new babies by receiving blood samples from two different toddlers. Their second job is to take care of the young until they can walk and talk by themselves, and change their own diapers."
"Alright, parameters set and ready to go," one of the crew called, "Ready on your mark, Princess Delly."
"FIRE THE TRANSMOGRIFICATION LASER!" the princess called. The bear shaped space ship opened its mouth and bathed the planet in an intense pink light. Soon, all of humanity would turn into either a toddler or a mommy, and nothing would ever be the same again.
"We're finally gonna have our first off-world colony!" Princess Delly cheered, "Ooh! I'm so excited I just might-" her cheers were cut off by the sounds of her emptying her bladder and her bowels into her thick diaper. It began to sag at her ankles as a bright blue blush spread across her cyan cheeks. "Uhh... set current excitement levels to code brellow... I need to change my diaper..."