"The Old General's Ability" 

Such a monster couldn't be distinguished from sober beasts except for their obvious appearance. 

The huge difference in appearance between beasts and monsters was the mere fact that no matter how strange a beast was, no matter how many different animal bodies it had on its body, beasts always looked good and majestic.

It was as if those strange body parts were just right for them. 

On the contrary, monsters, even if they were just the most basic reptile or insect, they all looked ugly and hideous. 

This was also why most reptiles and insects were monsters or ordinary ones instead of beasts because even ordinary insects and reptiles were often seen as ugly by human beings. 

No matter how ugly a hippopotamus was, it could not be uglier than a strange insect.