Saltamontes
“La canción de los saltamontes” is about Zael and Nephli, they are from a species which drastically changes depending on how they are born.
If they are born in the light of the sun, they develop wings. Like this, they are considered superior. But if they have an odd number of wings they are seen as malformed and are stripped of most of their rights, forced to live alone or most of the times sacrificed.
The ones born in the dark or night are exiled, and many go to live in the cavern cities. They are wingless and considered by the winged ones to be aggressive, uncontrollable and animal-like.
Everyone is born with their mouth shut, which has to be opened by a doctor when they reach a certain age. The ones with the odd number of wings are forbidden to talk, and their mouths remain closed forever. Those who live in the caverns do it by themselves in bad conditions, so their mouths tend to be crooked or badly opened.