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)

S-Rank Monster no "Behemoth" dakedo, Neko to Machigawarete Elf Musume no Pet toshite Kurashitemasu began as a web novel on Shousetsuka ni Narou on August 19, 2017. Micro Magazine-sha has released a revised and illustrated version of the series since March 30, 2018 under its GC Novels label. The series was published in English as I'm a Behemoth, an S-Ranked Monster, but Mistaken for a Cat, I Live as an Elf Girl's Pet by Yen Press under the Yen On imprint from July 21, 2020, to November 17, 2020.