Yellowfang's Secret is a teen fantasy novel written by Cherith Baldry under the pen name Erin Hunter. It is the fifth "Super Edition" in the Warriors novel series. Yellowfang's Secret was first released in hardcover on 9 October 2012.^[1] It focuses on a cat named Yellowfang, who lives with forest cats who call themselves Clans.

Yellowfang's Secret follows Yellowfang, the ThunderClan medicine cat (healer), during her early life in ShadowClan. Yellowfang trains as a warrior apprentice (a cat who hunts and fights), but realizes that she would do better as a medicine cat. The story in the book takes place at the same time as the other Super Editions Bluestar's Prophecy and Crookedstar's Promise. It is written for readers 8-12 years old.^[2]

Yellowfang is called Yellowkit when she is born. She is born in ShadowClan. Her parents are Brightflower and Brackenfoot. Her siblings are Nutkit and Rowankit. Yellowfang has a special power: she feels other cats' pain as if it were hers. When she is small, both she and Nutkit have pain in their stomach one day, even though Nutkit is the only one who is really sick.

When Yellowkit is older, she is renamed Yellowpaw. A cat named Deerleap teaches her how to be a warrior, where she will hunt and fight for her Clan. She becomes close with a cat called Raggedpelt. The other cats do not like Raggedpelt because the think his father might have been a house cat (Clan cats do not like house cats because they think they are lazy). Yellowpaw tries to help Raggedpelt find out who his father was. But when they find out his father really was a house cat, things become worse for Raggedpelt. Hal, Raggedpelt's father, rejects Raggedpelt, and then Raggedpelt kills Hal. Another female cat, Foxheart, also likes Raggedpelt, but Raggedpelt likes Yellowpaw.

Yellowpaw is eventually renamed Yellowfang, and she completes her training and becomes a warrior. Sagewhisker, the ShadowClan medicine cat, convinces Yellowfang that her ability to feel other cats' pain would make her a very good medicine cat. At first, Yellowfang wants to stay as a warrior instead, but later she changes her mind. Yellowfang becomes Sagewhisker's apprentice and takes the medicine cat's vows. In this book, being a medicine cat means never having a mate or kittens. But Yellowfang stays with Raggedpelt in secret, against the rules.

Yellowfang finds out that she is pregnant. Because this is against the medicine cat rules, Yellowfang gives birth in secret. Only one kitten survives. She names the kitten Brokenkit and gives it to Raggedpelt. The Clan thinks Foxheart is Brokenkit's mother. However, he is nursed by a cat named Lizardstripe, who is mean to him. Her kittens also bully him. Brokenkit grows up angry and misguided. Eventually, Brokenkit becomes a warrior and is renamed Brokentail. He eventually becomes the deputy (second-in-command) of the Clan. Brokentail trains the young cats of his Clan harshly. When Raggedpelt (who has become leader of ShadowClan and is now called Raggedstar) tells Brokentail it is too much, Brokentail pretends to agree, but seceretly plans to kill him, so that he can become leader of the Clan. Brokentail's plan works, and he makes it look like cats from another Clan, WindClan, killed Raggedpelt.

Brokentail becomes Brokenstar. He rules ShadowClan cruelly. Using his father's death as an excuse, he has ShadowClan attack WindClan, eventually driving them out. He begins training kittens before they are six months old, which is against the rules the Clans live by. He tells old cats to leave the camp and fend for themselves, which is also against the Clan's rules. When a kitten dies in battle, Yellowfang speaks up against Brokenstar's cruelty, which leads Brokenstar to set up another plan: falsely accusing her of the deaths of two other kittens, and banishing her from the Clan.

Yellowfang leaves and she goes to ThunderClan territory, where, exhausted by rage and hunger, she is attacked by a ThunderClan cat named Firepaw. After a brief fight, Yellowfang admits defeat. Yellowfang is taken to the ThunderClan camp, where she slowly comes to love ThunderClan, and is eventually invited to stay there for good.

A bonus comic scene at the end of the book shows Yellowfang killing Brokenstar with a poisonous berry, in an attempt to put right everything she has done wrong in her life.

Barnes & Noble said this book was "an epic stand-alone adventure." It has a ranking of 4.7 out of 5 stars on the Barnes & Noble website.^[2]