normally monstergirls kill no human without reason but kill monstergirls sometimes monster fromtheir own race or other races? some races hate each other and fight with no mercy here some exsamples: 1.elf and dark elf 2. elf,dark elf and dwarf 3. vampire and werewolf 4. honeybee and hornet if a monstergirl from the same race steal a man maybe she kill the monstergirl who have the man or will killed if she trying it. other cases are also possible when monstergirls attack mermaids to get her blood.