S-Rank Monster no "Behemoth" dakedo, Neko to Machigawarete Elf Musume no Pet toshite Kurashitemasu (Im Behemoth An Ranked Monster But Mistaken For Cat Live As An Elf Girls Pet)

Nobody asked to be a cat!

After dying in a fight against the forces of evil, a knight is shocked to discover that instead of being reborn as a hero of humanity, he starts his new life as a behemoth-one of the most powerful monsters in the world! The only problem is that a baby behemoth looks an awful lot like...an adorable house cat?! Things grow even more confusing when a beautiful elf adventurer rescues him from the brink of death rather than finishing him off. This house-cat-slash-knight's baffling journey is just getting started...

(Source: Yen Press)