"Redtail was her deputy for many, many, moons. She won't want to let him go too quickly. He was one of the best warriors. Not as big and powerful as Tigerclaw or Lionheart, but quick and clever."—Graypaw about Redtail in Into the Wild, page 45
Redkit is born alongside his littermates, Spottedkit and Willowkit to Swiftbreeze and Adderfang. Their older siblings are Patchpelt and Leopardfoot. Redkit is seen with his littermates and mother just before the Clan meeting.
He is later made an apprentice, with Sparrowpelt given to him as his mentor.
During a fight with RiverClan over Sunningrocks, Redtail dies at the claws of Tigerclaw, an ambitious ThunderClan warrior who hopes to become the next deputy of ThunderClan. Tigerclaw lies about Redtail's death, telling the rest of ThunderClan that the RiverClan deputy, Oakheart, had killed Redtail, and that he had killed Oakheart to avenge his fallen Clanmate's death.
However, Tigerclaw's apprentice, Ravenpaw, witnessed what actually had happened. Oakheart had been killed by an accidental rockfall while he and Redtail were fighting, and then Tigerclaw killed Redtail, since Oakheart was dead.
Firepaw later discovers the truth in his investigations of Redtail's death. Ravenpaw describes Redtail as very brave, and Bluestar refers to him as a noble cat. Dustpaw is devastated when he hears that his mentor has died. Bluestar then chooses Lionheart as the next deputy of ThunderClan, instead of Tigerclaw.
Redtail appears as one of the cats who gives Firestar his nine lives. With his life he gives Firestar justice, and thanks Firestar for revealing the truth when no one else could, referring to Firestar exposing Tigerclaw's role in his death.
Later, Redtail is mentioned when Ravenpaw comes out of the barn he and Barley share. It is said that Ravenpaw was the only cat besides Tigerstar that knew of Redtail's death.
Redtail appears when Jayfeather is going over the cats who gave Firestar his nine lives, shortly after the leader's death. Jayfeather notes that he gave Firestar courage, though Redtail actually gave him justice.
- It is odd to note that Redtail fathered Sandstorm, as male tortoiseshells typically cannot father kits because they are commonly born sterile.
- In The Last Hope, it is said that he gave Firestar a life of courage, when he really gave him a life of justice, and Lionheart gave him courage.