When he is mistakenly recognized as an Elemental Cat, Aria is warned that the species can crossbreed and "assault" their proprietors when in heat. I'm a Behemoth, an S-Ranked Monster, but Mistaken for a Cat, I Live as an Elf Girl's Pet: Aria, an Elf woman, finds the titular Behemoth, a reincarnated unnamed knight, who seems like a kitten and was mortally wounded.