It had taken him nearly a day to realize that he should name them.
A day of coming to turns with his transformation, something Hamato Yoshi's mind still wrapped around but sluggishly. It almost still hurt—the prickled feeling of fur on his body, the whiskers brushing against the sewer walls if he got too close … the tail that threw him off-balance every other step.
Yoshi had nearly forgotten the helpless, stumbling little ones at first, when his own turmoil was fresh. The smallest one had nearly made it to the sidewalk before he remembered them in a rush, scooping the four into his arms and running deeper into the maze of buildings, towards the nearest sewer grate.
The next hours were spent in dazed, dark wandering, with the turtles following behind him on unsteady feet. Yoshi was shocked later by his own neglect: what if one had fallen into the sewage, or fallen too far behind?
But he had been lucky. Eventually, he found himself in an old subway station, decently warm and dry. Exhausted, and still relatively numb to his new world, he pulled the little turtles close to him in an alcove of the station. Then they slept.
The morning after, he looked them over thoroughly. The transformation had not taken away the gentle touch of a parent, and he picked up each squirming, cooing creature one at a time, learning that they all, at least, appeared healthy, and all were male. The pet store man had been right.
But how healthy could a mutant be? Were they more human or turtle? Alien? Yoshi had no clue.
He had been reading a book before he left his apartment that day. Western art history; he had always been open to learning something new. So he picked their names on a whim, from what he could remember. It was that morning's distraction while he observed them, and for that he was grateful.
What he learned was that they were toddlers, nothing more. They just happened to look strikingly different from the human ones.
Leonardo was affectionate and curious, clinging to Yoshi's knees and pulling at his fur. He seemed to have the best grasp of how to walk without stumbling. Raphael already pushed and shoved, especially with Leonardo for the coveted place in Yoshi's lap. He pulled them apart gently each time, patiently.
Donatello was cautious; he cried easily, especially when one of the others did something to upset him. He examined everything, everything he could get his hands on—including the used needles and old batteries that Yoshi had to snatch away from him. Michelangelo was the smallest and the chubbiest, with large eyes and a sweet smile. He ran when he could, though it almost always ended in him falling face-first.
Yoshi found that he had no time to fret over himself and his new appearance, when chasing after the four of them took up such energy. It was not as if he had no experience with children … had he not been a father once before? These were rambunctious boys, not the infant daughter he had lost. It made the sting less sharp.
He found food for them later, after letting them play themselves into exhaustion and fall asleep in a heap. Swiftly he reached the surface again, then returned, with a box of leftovers from behind a restaurant. They had to eat—Yoshi had no time to learn whether they could even take human food.
Fed and content, the four slept again, a pile in Yoshi's lap. Now he thought hard, on how to build his life again. The surface was not the place for them, that much was clear. But there were possessions to retrieve, from that surface apartment, a safe home to find … these thoughts kept him occupied when the turtles did not.
Since they were, after all, his children now. What else could he call them?