Siete Cabezas (2017) online

Marcos, a withdrawn park ranger, sees the fragile balance achieved in his isolation collapse with the arrival of a couple of biologists investigating strange bird deaths. Unfortunately, the desire and envy for normality represented by the couple awaken the monster he has been trying to control. His face, his legs, and his arms don't belong to him and as the desperation becomes uncontrollable, he can only see one way out: mutilation