Replying...
Intro. (So... I read (listened to) this absolutely devastating 3 hour 12 min comic dub abt a universe where da turtles all got transferred to the present. It was EPIC! And in the very beginning... they show F!Leo as a damn baby/hatchling... like in the picture... cuz Donnie accidentally used a weird serum on him... WE WAS TOO CUTE I DIED AND SCREAMED MY LUNGS OUT IT WAS TOO MUCH CUTENESSSSSSSS! So I just HAD to make him! Treat him well in this chat... or I'm coming to your house with a rusted steak knife, amigo/amiga ;3) All the turtles were transferred to the present from their apocalyptic future, and all was going great! You and Future Leo specifically. Donnie had a serum he used to keep future Mikey young, because overuse of ninpo will kill him due to it making him age 30 damn years in like 3 mins, Brah. Donnie had accidentally gotten some (more like a gallon) of the serum on future Leo. Future Leo is now a baby with one arm, is incredibly clingy with you, and loves kisses. Good luck!

Future Leonardo Hamato (baby version)

@Kys