Whitestorm, a large white tom with yellow eyes, was a senior ThunderClan warrior in the original series. He was one of the few cats who always treated Firestar with kindness when he is first brought into ThunderClan, and often gave him advice when he sensed that Firestar is troubled. Whitestorm was a gallant fighter, but was always more reserved rather than bloodthirsty and carries a thoughtful demeanor.
Though he was the most experienced senior warrior in the Clan, Whitestorm does not harbor any ambition toward becoming Clan leader and as such offers his wisdom to younger cats entirely out of good will. He assisted Firestar with the burdens of being Clan deputy during Bluestar's depression, and takes over for him occasionally when Firestar's duties call him elsewhere. Being Bluestar's nephew, as her sister Snowfur was his mother, Whitestorm was one of the warriors who were closest to her, and often stayed by her side in order to comfort her and maintain her sanity when she succumbed into paranoia through the later books. Eventually Firestar appointed Whitestorm as his deputy in appreciation for all his advice, a promotion he was unexpectedly pleased about (a trait that Firestar admires, given the ambitions of previous cats he had encountered). Whitestorm was killed by Bone during the battle with BloodClan in The Darkest Hour, his last wish being that Firestar appoint Graystripe as his new deputy, which is granted.
Whitestorm's mate was Willowpelt. With Willowpelt he fathered Sorreltail, Sootfur and Rainwhisker. As such he was the grandfather of Sorreltail's kits, Cinderheart, Molepaw, Honeyfern, and Poppyfrost. And is the great-grandfather of Molekit and Cherrykit (Poppyfrost's kits). Snowfur's parents were Stormtail and Moonflower making them his other set of grandparents. His aunts were Bluestar (Snowfur's sister), Sweetpaw and Rosetail, because their brother, Thistleclaw, was his father, making Poppydawn and Windflight, their parents, his paternal grandparents. He was mentored by Patchpelt, and later mentored Patchpelt's niece, Sandstorm, and later, Sandstorm's cousin Brightheart. He is great-nephew to Pinestar (Poppydawn's brother), and great-grandson to Sweetbriar (Poppydawn's mother).