In concept art, Erabus seems to resemble an equestrian with black eyes, as well as long arms with muscular hands and cephalopod tentacles.
Erabus came to Earth shortly after Redmoon arrives from the moon. The Japanese Self Defense thought they could lure the two kaiju together so they could defeat each other, but they turn out to be the same species and of opposite genders. They soon have a son dubbed Hafun, who is killed later on. Hafun's parents go berserk and destroy cities, but Godzilla arrives and defeats them.