Bluestar is a pale blue-gray she-cat with blue eyes.

Bluestar was a leader of Thunderclan in the forest territories. She was a proud and deeply committed leader. Bluekit was born to Moonflower and Stormtail alongside her sister, Snowkit. She was apprenticed early as Bluepaw with her mentor being Stonepelt. However, after a devastating battle, Moonflower was killed and Stonepelt retired, resulting in Sunfall being Bluepaw's new mentor. Goosefeather gave her a prophacy, though she didn't think much of it. After becoming a warrior, Bluefur raised Whitekit, Snowfur's kit, as her own after the death of her sister due to a Thunderpath accident while chasing off Shadowclan trespassers, and Bluefur fell for a Riverclan warrior, Oakheart, becoming pregnant with his kits. Bluefur then realized she could not be loyal to her Clan when her heart lay somewhere else. At first, she raised Mistykit, Stonekit, and Mosskit in ThunderClan with Thrushpelt acting as their father; however, in order to become deputy instead of the ambitious Thisleclaw, whom she feared would destroy ThunderClan with his thirst for battle, she gave up her kits to Oakheart to live in RiverClan, and on the journey there, Mosskit perished from the cold. Bluefur mentored Frostfur and Runningwind, and later succeeded Tawnyspots as deputy. After Sunstar's death, she became leader as Bluestar.