User blog comment:Kogath/Monster Hunter 4 Ultimate for the Nintendo 3DS/@comment-6050823-20141012062734/@comment-25217415-20141012153526

Even in the name sounds like the nemesis of Rathalos:

rath-al-os: Sound like that came from "wrath"+"os"

sere-gi-os: Sound like that came from "Serenity"+"os"(but don't fit quite well the monster)