My Hero Academia is a world filled with heroes. These heroes have mutations called quirks that give them superhuman powers. These powers can be categorized into three groups: emitter quirks that allow control over something, transformation quirks that allow for transformation, and mutations. One student at UA, Fumikage Tokoyami, has a mutation quirk like no other.
Tokoyami can be considered one of the most influential students in Class 1-A with Dark Shadow. What's so strange about Tokoyami isn't Dark Shadow but his bird head. As far as everyone knows, Tokoyami's bird head has nothing to do with Dark Shadow and his abilities. So, why does Tokoyami have a bird head?
Inherited Quirk
One reason that Tokoyami has a bird head is the type of quirks he has. Dark Shadow is categorized as an emitter quirk because Tokoyami can summon and control him at will. Well, control him the best that he can consider that Dark Shadow is sentient. This means that Tokoyami's bird head mutation gives Tokoyami two different quirks.
Something that is known in My Hero Academia is that quirks are inherited. A great example is Shoto Todoroki, with his fire and ice emitter quirk. He got his fire quirk from his father and his ice quirk from his mother. This would mean that someone in Tokoyami's family must have some type of bird quirk that gave him the bird mutation. There could also be a member of his family with a similar shadow emitter quirk. This theory can't be proven because fans haven't been introduced to Tokoyami's parents or seen what they looked like.
An argument that Tokoyami's appearance changed after getting Dark Shadow could be made, but a manga panel disproves this. In this panel, Tokoyami goes down a slide as a boy, and he still has his bird head. This means that he was born with the mutation, and Dark Shadow copied his appearances. Instead of Tokoyami changing to match Dark Shadow.
That It?
The reasoning behind Tokoyami's mutation might be disappointing compared to his incredible ability. In reality, Tokoyami's mutation was never supposed to be anything more than a mutation. Instead, it can be assumed that Tokoyami's mutation was added for several reasons. The first reason is that mutations don't have an explanation. Yes, most mutations are inherited, but there is no reason behind them. Many people in this world will have a useless mutation and have to live with it. Tokoyami is just another example of how this world works.
Another reason is character design. At the end of the day, My Hero Academia is a story, and all the characters were designed for certain reasons. Tokoyami was probably given a bird head to match his dark personality. Making him stand out in comparison to his peers. Tokoyami is a reserved character interested in the occult and dark fantasy. Having a bird head matches his interests. Of course, the simple answer to this question is that the creator wanted him to have a bird head.
No matter the real reason, Fumikage Tokoyami is one of the most interesting characters in My Hero Academia. He represents everyone who loves the weird, and fans adore him. In future installments of both the manga and the anime, everyone will be waiting to see if more is presented on Tokoyami. Fans can stream My Hero Academia on Crunchyroll, Funimation, and Hulu until then.