[ivzhh]

It seems [Edie Freedman](https://www.itworld.com/article/2708642/history-of-the-o-rei...) chooses the animal based on the description from the authors:

> I ask the authors to supply me with a description of the topic of the book. What I am looking for is adjectives that really give me an idea of the "personality" of the topic.... Sometimes it is based on no more than what the title sounds like. (COFF, for example, sounded like a walrus noise to me.) Sometimes it is very much linked to the name of the book or software. (For example, vi, the "Visual Editor," suggested some beast with huge eyes).

My guess is the animals of the series is kind of decided by the first animal. Several Kubernetes (operators)/Cloud-native books are with birds on front page.