Redtail is a dark tortoiseshell tom with a bushy dark ginger tail and amber eyes.

Redtail was a Thunderclan deputy under Bluestar's leadership in the forest territories. He was born as Redkit to Swiftbreeze and Adderfang alongside his sisters, Willowkit and Spottedkit. As an apprentice, Redpaw was mentored by Halftail and felt loyalty to Tigerclaw when the tom saved him from a hawk. However, after becoming a warrior, Redtail realized Tigerclaw's true intentions and stopped having any loyalty towards him. He mentored Mousefur and Dustpelt and later became Bluestar's first deputy. Thereafter, over a battle at Sunningrocks, Tigerclaw murdered Redtail in hopes of becoming deputy. Redtail ascended to Starclan and thanked Fireheart for revealing the truth over his death, giving him one of his nine lives. He took part in the battle against the Dark Forest, and, later, he ventured into the Dark forest to help defeat Ashfur.