His friends would probably take care of him. Midoriya would be very eager to help, using his kind-hearted nature. He would make sure Todoroki is fed and comfortable.
One popular baby Todoroki fanfic could be 'Baby Todoroki's Adventure'. It might focus on his early days and how his unique quirk starts to show in a cute and innocent way. Another could be 'The Little Todoroki' which could explore his relationship with his family members at a very young age.
You can try searching on websites like Archive of Our Own (AO3). It has a large collection of fanfics, and there's a good chance you'll find some great baby Todoroki fanfics there.
Well, in this kind of fanfiction, probably his friends would be super shocked at first. They might struggle to take care of him as he's now a baby. His powers could also be affected in some strange ways, like they might be uncontrollable or show up in unexpected forms since he's in a baby's body.
Family is a common theme. Since Shoto has a complex family situation, fanfictions often explore how his family members interact with him as a baby. For example, how his father might view a baby Shoto with his powerful quirk.
There's 'Baby Shoto's Adventures'. This fanfiction focuses on how baby Shoto's quirk starts to show in cute and innocent situations. It has a lot of endearing moments between baby Shoto and the other characters in his world, like his family members. It really brings out the charm of a young Shoto Todoroki.
One idea could be that all his friends at UA plan a surprise birthday party for him. They decorate the common room with his favorite colors, blue and red. Another plot could be Todoroki spending his birthday with his family, trying to reconcile with his father on this special day. Maybe he receives a heartfelt gift from his mother that has a deep emotional significance.
Todoroki's character development in time travel fanfictions can be quite profound. He may start as a somewhat aloof character, but through time travel, he begins to understand the importance of relationships more deeply. When he travels back and witnesses the relationships he could have had or lost, it makes him cherish the ones he has in his original timeline. His view of heroism also evolves. He realizes that being a hero isn't just about using his powers but also about making the right choices at the right time, which is especially highlighted when he has to make decisions that could change entire timelines.