The Beast Within

Not your average boy

Izuku Midoriya isn't exactly your average typical high school Quirk user.

He's a little more complicated than that.

You see, everyone has a Quirk, but Midoriya's is special. 

He was born with a rare Quirk that makes him turn into any animal he thinks of. He can force the animal he becomes to evolve into a more powerful, faster and stronger version. He also has the power of partial transformation. (For example, he could choose to only turn his legs into a wolves legs).

Sadly though, there is always a drawback. Midoriya has a limit of how long he can be a certain animal for. He can only be an animal for a day. Otherwise, he slowly gains the characteristics and behaviour of that specific animal, and once that day has past, he is that animal forever. And because his transformation makes the animal so much more powerful, as soon as he has permanently turned into that animal, he becomes dangerous, vicious, savage, and there's no turning him back into a human. And as if that wasn't bad enough, his Quirk has another disadvantage: If he uses his Quirk for a full day, he will be exhausted after transforming back into a human and therefore will need a minimum of 8 hours for his Quirk to recharge and restore himself so he can use it again the next day.  

Author's Note: @TheInfiniteweeaboo you happy now!?

Legend says, there is a cure that could transform him back into a human but there are only small doses of it and they are scattered all over Japan. 

As a kid, he wasn't aware of his Quirk at first. And once he was told to draw his favourite animal in school. Naturally, he thought about it before he drew it. And his favourite animal was a wolf. 

Not long after that, he slowly began to develop green wolf ears to blend in with his hair, and a small tail which grew bigger as he got older. He wasn't born the best at running, but since gaining his wolf power, his teachers and classmates began to notice that Midoriya was getting increasingly faster by the day. 

When Midoriya had first developed these wolf features, he didn't notice at first. 

He was only about 5 years old at the time so he was more interested in stuffing his face with noodles.

The wolf ears blended so well with his hair that not even his parents noticed until it was too late. As for the tail, it was a gradual change, it was incredibly small at first, and then it grew and grew until it grew the maximum length for a 5 year old. And as soon as that happened, people started noticing. And as soon as THAT happened, Midoriya noticed. 

Since it took so long for anyone to notify Midoriya of his new wolf features, he had exceeded the time limit. And now he was permanently stuck with wolf ears and a tail forever. 

He could still change into any other animal he chose, but his wolf ears and tail would still be there when he turned back into a human. 

At first he didn't like it, and was distraught. But after a while he got used to it, he thought it made him look cool and wild. And the girls in his class found it cute. 

So now, follow Midoriya as he embarks on adventures as a wolf hybrid.

Author's update 10/10/17: Changed this chapter a little so now Deku also has another drawback where he needs to wait until his Quirk is restored as well as having the risk of permanently turning into an animal he chooses. His Quirk is a little complicated as you can tell. The reason why I changed it is because I added the second drawback in a later chapter and forgot to put it in this one first so a couple people were confused as to why I was suddenly adding another drawback so yeah.. soz..