Beheneko: The Elf-Girl's Cat Is Secretly an S-Ranked Monster!
Sランクモンスターの《ベヒーモス》だけど、猫と間違われてエルフ娘の騎士（ペット）として暮らしてます , I'm an S-Rank "Behemoth" Monster, but I'm Living as a Pet of an Elf Girl, I'm a Behemoth, an S-Ranked Monster, but Mistaken for a Cat, I Live as an Elf Girl's Pet
After dying in a fight against the forces of evil, a knight found himself reincarnated as one of the most powerful monsters in the world: a behemoth. Problem is, he has to grow up before he can really show what he can do, and a baby behemoth looks an awful lot like...a housecat? And when an elf adventurer decides to take him in, she may need his help as much as he needs hers.
