Darktail/Main article

Darktail is a big, muscular, glossy white tom with black spots breaking up the white, black spots around his blue eyes, huge paws, and a long black tail.

Darktail is born with no known name to Smoke, a kittypet, and Onewhisker of WindClan. He is the sole survivor of their litter. Smoke asks Onewhisker if she can join WindClan with their kit, but Onewhisker rejects them, partly for their own safety and partly out of fear of his Clanmates' wrath. Enraged, Smoke turns on him, swearing that she will raise their kit alone and teach him to hate the Clans for this rejection.

He appears many seasons later, as Darktail, and comes across SkyClan at the gorge. He cunningly convinces Hawkwing to take him to SkyClan to get treated by Echosong, claiming he breathed in smoke from a fire. He lives with SkyClan briefly and is treated with respect, but also with suspicion by a few members of the Clan, including Hawkwing. After sending several of SkyClan's cats on a false and dangerous journey and later revealing his true intentions, Darktail leads his band of rogues to take over SkyClan's camp and they drive them out of the gorge. The battle is a bloodbath and Darktail and his rogues kill many of SkyClan's warriors, including the deputy Sharpclaw.

Alderpaw leads a small group of journeying cats to find SkyClan in the gorge and bring them back to the Clans. When they arrive, Darktail introduces himself as the leader of SkyClan and welcomes them to their camp. They quickly realize that these cats do not follow the warrior code, and Darktail is a liar. They escape overnight after being held captive and unknowingly leave a trail back to the Clans for Darktail and his rogues to follow.

Darktail and his rogues arrive at the lake territories and viciously attack WindClan. ThunderClan warriors arrive and Darktail and his rogues are driven away by the Clans, but not before killing Furzepelt and injuring many others. Darktail and his rogues then settle near ShadowClan territory. His strong method of leadership appeals to many ShadowClan cats, who think Rowanstar is a weak and spineless leader. Darktail and his group convince several young ShadowClan cats to follow him, including Sleekwhisker, Needletail, Violetpaw, and Juniperclaw. Meanwhile, ShadowClan struggles under divided leadership, which gives Darktail the opportunity to walk in and take over ShadowClan, forcing out Rowanstar, Tigerheart and Tawnypelt. With many new cats with him, he renames his group the Kin. Deciding that Darktail and his rogues are too dangerous to be allowed to stay, ThunderClan, WindClan, RiverClan and the ShadowClan refugees attempt to drive out the Kin. This ultimately fails when Darktail goes one-on-one with Onestar and whispers something to him, causing the leader to order WindClan's retreat. With WindClan gone, ThunderClan, RiverClan and the ShadowClan refugees fall back, allowing Darktail to gain victory.

With the Kin being strengthened by new numbers, Darktail boldly decides to attempt to drive out RiverClan, which took the most damage in the battle. After a terrible and bloody battle, Darktail and his rogues defeat Mistystar and her remaining cats, killing several of her warriors and injuring many others. Darktail allows RiverClan to flee to ThunderClan, but refuses to allow them to take the most injured cats, Brackenpelt, Icewing, Mintfur and the deputy Reedwhisker, who is also Mistystar's son, with them. Instead, Darktail decides to keep them as prisoners. He also refuses to allow RiverClan to take the bodies of their slain Clanmates for burial, and leaves them to rot in the open. Darktail and his rogues set up camp in RiverClan's old camp, and he begins his tyrannical rule.

During Darktail's reign, many former ShadowClan cats regret joining the Kin, and leave for shelter in ThunderClan, but some do not make it and are instead drowned in the lake by Darktail and his accomplices. Eventually, the remaining ex-ShadowClan cats and the RiverClan prisoners rise up against Darktail and his rogues and force them of RiverClan's old camp. Having lost one of his camps, Darktail sets his sights on WindClan. It is then and there that Onestar is revealed to be Darktail's father, and with the arrival of SkyClan, the Clans decide to push out the Kin in one, final decisive battle. The Clans attack the Kin in their camp, driving them into the open, where Darktail is confronted by Onestar. The father and son fight each other into the lake, where they both drown one another. With their leader dead, the Kin flees the area and soon disbands without Darktail.

Although Darktail's death was thought to bring peace, his actions leave lasting effects on the Clans, such as many territory disputes, ShadowClan being annexed into SkyClan, RiverClan closing their borders, and a year-long conflict.