Did he mention that being a baby sucked balls? Because it did. Big, nasty hairy ones.

Katsuki wanted to get this show rolling. He didn't even know what kind of world he'd been dumped into or how his quirk would show up. But no matter how much he wiggled, squirmed, or screamed, his body wouldn't even turn over let alone hold in its own poo or say any words. Ugh.

So, in order to preserve his sanity, he let his mind drift for the first few months through his memories. He lingered on his death the most, trying to comprehend the strange mix of regret and satisfaction. He was glad that Deku lived. He was glad to give the self-sacrificing idiot a taste of his own medicine. But dying had been the last thing he had wanted to do. He just had so freaking much going for him. He still had things he need to straighten out, relationships to get right, people to make up to, villains to end.

Whenever he didn't escape into sleep or memories, he was looking back at his parents, specifically his mother, watching her humiliate herself with baby talk and cooing. Heck yeah it made him laugh, which only encouraged her. If only she knew that her baby boy had the mind of a teenager. Probably best that she didn't.

But even as he internally mocked her, his heart solidified a new resolution:

I'm going to be a better son to you this time.

So he cooed. He giggled. He did his best not to cry too much, even when all he wanted to do was explode and swear every last vulgar profanity he could think of. He did his best not to think about breast feeding (oh god, he tried), and definitely went space cadet when he had to get his diaper changed. What was pride when you were little more than a drooling lump of flesh? At least no one he knew was around to see him like this. And even if they were, all they'd see was a damn fucking adorable baby. Probably the best baby that ever existed.

Time past. There was no way he could keep track of it. But his body grew more responsive to his desires, his vision cleared, and his first teeth came in so he could get to chomping on real food other than, you know…tits.

His first surprise came when he found his home to be, not a house, but a tent. A freaking cave man tent made of canvas and animal skins, decorated with artful rings of feathers, bones, dream catchers, you know, tent-people shit. His parents wore leather and furs. The furniture was wood and, get this, more furs. He was surprised that the freaking carpet at least had some color in it that indicated some kind of dyed wool.

And whenever his mom would take him outside to walk him around, it was only to see more tents and more tent-people. He couldn't even laugh whenever random idiots would make faces at him, because he was too caught up coping with an existential crisis.

Plumbing. Couches. Microwaves. TV. Internet!

He changed his mind. Screw having another life, he'll take moving on. Being a wispy ghost would be better than roughing it with the Flintstones.

Then he got woken up in the middle of the night by a commotion. His mom brought it a haggard young woman with green hair, clutching a bundle to her chest.

He had a bad feeling about that bundle. And when his mom coaxed the very, VERY familiar, dirty looking woman to let her see what was in it, she gave a great shout.

"Oh! You poor thing!"

And, still in the middle of the night, mind you, Katsuki got introduced to another green haired baby. Green, curly-hair.

The baby didn't need freckles or more growth to instantly know who it was.

"DEKU!?"

Yeah, he meant to say Izuku. Bad habits die hard.

But since he was a baby, it came out like this:

"BUBU!"

While his parents lost their ever loving shit at his reaction. ("Oh my gosh, look how surprised he is! It's like he's never seen another baby before!") Katsuki quickly did a once over on the bedraggled Auntie Inko and the rather sad, snotty faced baby Izuku.

Neither of them looked good. And they smelled like smoke.

But besides that.

"Why the hell did you follow me?" he screeched. "Are you gay or something? Masochistic gay? 'Cause I swear, no one would pay for this bromance."

But, again, since he was a baby, all that came out was babbling, and poor baby Izuku wasn't even looking at him anymore. He really hated this baby shit.

And, thus, his life had come full circle. Deku and him. Him and Izuku.