ive seen a cat, rabbit, vampire, werewolf mls BUT I HAVE NOT SEEN AN OCTOPUS ONE DOES ANYO...

https://www.mangago.zone/read-manga/monster_in_a_bubble/

This GL sort of counts, the FL is a demon based on the Cthulu entity, who resembles an octopus:

https://www.mangago.zone/read-manga/working_overtime_to_destroy_the_world/

https://www.mangago.zone/read-manga/oneness/