A Mother overcome with grief when her son Santiago dies takes a piece of her son's lung, keeps it in a jar, feeds it, and watches it become the monster known as Monstrilio. We follow Monstrilio on his journey from 'feral animal' to 'childlike' to 'teenager' to 'monster'. 

Personally, even though this is classified as horror I can say that I anyone can read this as the 'horror' is minimal. And like, despite being a monster I found Monstrilio quite cute and enjoyed reading about him, especially in his young monster form when he was just flying around and terrorizing people. 

Cordova has a really vivid imagination and tells the story in a really immersive experience that makes you feel like you're right there in the story. Monstrilio's journey with self-discovery is both heartfelt and compelling, and the supporting cast of characters adds depth and intrigue to the narrative, especially since you get to follow their POV's as well. 

One of the biggest negatives for me was that the story is more 'slice of life' and while I do like those types of novels typically, I don't know if 'this story' fits that narrative.

Overall, I thought that this was really well done and can understand why it was part of the Goodreads choice award. I'd definitely read additional works by this author.