* CompleteMonster: Most of the villains in the series are entirely evil and sadistic with no real redeeming qualities.
* JerkassWoobie: Isaac Nettle. You can't help but feel sorry for him as [[spoiler:he grieves over the death of his son, even though he [[AbusiveParents was abusive]] towards him. It was heartbreaking when he found the owl pellet containing Jenkin's mousebrass.]]
* UncannyValley: The illustrations, to some extent, but considering the book's content this is likely intentional.
* WhatDoYouMeanItsForKids: While these books feature cute animals, many of them are subjected to violent, absolutely horrific deaths such as being skinned alive, decapitated, or having their body slowly eaten away by a deadly poison.
* TheWoobie: There are plenty of these, with Audrey and Ysabelle being among the most notable examples.