Board Thread:General Discussion/@comment-27907368-20160412010659/@comment-27620479-20160509051326

Monsters do not recognize humans by their looks.

Humans show less variety than monsters in that their shape is roughly the same. Asgore, who is confrmed to have killed six humans and adopted one before, should already know the pattern. Yet, he doesn't recognize the protagonist on a genocide route. He doesn't even ask if they are a human, instead assumes them to be an unknown kind of monster.