https://loveheaven.net/manga-i-am-behemoth-of-the-s-rank-monster-but-i-am-mistaken-as-a-cat-and-i-live-as-a-pet-of-elf-girl-raw.html <-- Chap 31-32-33 is out by week ago still not translated sadly.
S-Rank Monster no Behemoth Dakedo, Neko to Machigawarete Erufu Musume no Kishi (Pet) Toshite Kurashitemasu