Minecraft: Mobestiary

The naturalist is a scholarly human in the world of Minecraft and the fictional writer of Minecraft: Mobestiary by Alex Wiltshire. They has supposedly made it their life’s work to study Minecraft’s mobs and write their findings into an encyclopedia about the creatures and animals.

Creditability of the Naturalist
The naturalist was revealed to be an unreliable narrator who places bias on their own beliefs over evidence, as seen in this quote by the author:

"Hello! If you read the Mobestiary carefully, you'll notice that it's written from the point of view of one particular naturalist who tends to put their own theories and ideas among the facts, and maybe doesn't even have personal experience of the creatures they're writing about. So you should decide for yourself if you agree with them :)"

- Alex Wiltshire on the creditability of the Naturalist.

Minecraft: Mobestiary
The Naturalist explains how each mob works in detail according to his perspective in the Minecraft world. Most of the writing focuses on the in-game mechanics of each mob, but occasionally describes or shows information from outside of the game. Such as the origins of the killer bunny, TNT shown inside a creeper, and the superstition of the chicken being a spy. There are also dissections of some of the mobs showing organs, bones, gas, magma, gears, and/or redstone depending on the mob.

Trivia

 * A naturalist is someone who studies natural history and practices naturalism in the forms of art and writing.
 * It is actually confirmed by author Alex Wiltshire that not everything in the book might be canon. https://imgur.com/eQVpq8u