* CompleteMonster: Grizraz Hearteater became jealous of his older and younger brother and grew to hate cats in general. Hearteater summoned a {{Hellhound}} to kill as many cats as he could, and also ended up killing one of his brothers. Ever since then, Hearteater has hid underground in [[{{Hell}} Vastnir]] to avoid being detected and also to avoid the light. Hearteater hates [[{{God}} Meerclar Allmother]] and wants to destroy all of Her creations. Over the centuries he's become an AnimalisticAbomination and has been rearing monstrous minions to slaughter cats and kidnap slaves while he waits to start the apocalypse. Hearteater sits upon a throne of various tortured and dead animals, where all he does all day is [[ImAHumanitarian eat the cats]] that his servants bring him. At the end of the novel, Hearteater decides to show his true power by turning his mound of animals into a deformed, vaguely hellhound-like monster only called "the ''Fikos''" ("terrifying badness"), which slaughters multitudes of cats on both sides.
* EndingFatigue: Many consider everything after the mound and up to [[spoiler:Tailchaser finding Hushpad]] to drag.
* {{Fanon}}: Tangaloor Firefoot is a tortoiseshell. He's never described as such, but he's black-furred with unusual red paws. This is presumably due to his divine heritage but such a coloring wouldn't be possible in real life without being tortoiseshell. Though it should be noted that male tortoiseshell cats are extremely rare in real life, due to how cat genetics work (and when they occur, they're pretty much always infertile).
* FriendlyFandoms: With ''Literature/WarriorCats'', a 2000s franchise about cats living on their own. Many ''Warriors'' fans like it as a darker, more mature alternative to the ''Warriors'' series, while many ''Tailchaser's Song'' like ''Warriors'' as a SpiritualSuccessor.
* HardToAdaptWork: A [[LighterAndSofter child-friendly]] animated adaptation was greenlit, however [[DevelopmentHell nothing has been heard of it]] since its announcement. The fantasy book is rich in lore, has a large cast, and has quite a bit of violence, but it stars perfectly normal, non-FunnyAnimal cats. As a result, it's hard to adapt without severely watering it down into a LighterAndSofter adaptation. Kids aren't interested in it because it's more ''Literature/WatershipDown'' than ''ComicStrip/{{Garfield}}'', but adults don't want to see a film about talking cats.
* JerkassWoobie: Skinwretch. He's a villainous wretch, but at the same time he's such a sniveling little thing that he's just pathetic enough to be pitiable after he loses his sense of smell (which is his main way of seeing the world due to his blindness).
* NightmareFuel: Everything concerning Gizraz. He's an inhumane abomination whose only emotion is pure-hatred. All he does is sit around on his throne (which is made of dead and half-dead cats!) and eat other cats.
* PopularWithFurries: It's a cornerstone of pre-2000s {{xenofiction}} and was widely-acclaimed amongst cat fans upon release. It hasn't faired so well fandom-wise, though, as it doesn't receive that much fan-works.
* StoicWoobie: Poor Roofshadow. She was looked down upon by her clan for having interests besides looking for a mate, and then her entire clan was mercilessly slaughtered and torn to pieces when she came back from a walk. Much later, Roofshadow is enslaved and goes through hell while under the mound.
* SpiritualSuccessor: The book is basically ''Literature/WatershipDown'' with cats.
* ValuesDissonance: The story about Firefoot meeting Windflower could be interpreted as homophobic or transphobic. Firefoot meets a neutered tomcat who is so effeminate that he looks and sounds like a female. Upon learning he's a male and that humans made him so androgynous, Firefoot gets very upset. The tale is told by cats as a cautionary tale against neutering and against humans.
* WhatDoYouMeanItsNotForKids: The original cover features cute looking cats on the cover and the book is about talking cats. ''Tailchaser's Song'' is inspired by the child-geared ''Literature/WatershipDown'' but it isn't aimed at kids.
* TheWoobie: Pouncequick is only a kitten but he goes through a lot of trauma over the course of the book, plus he [[spoiler:loses his tail]] and he's already lost his parents. Even Tailchaser is unnerved by his change in demeanor towards the end.

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