|“||Keep your eyes open, Fireheart. Keep your ears pricked. Keep looking behind you. Because one day I'll find you, and then you"ll be crow-food.||„|
|~ Tigerstar (Forest of Secrets)|
When he was a kitten, his father, Pinestar left ThunderClan to become a kittypet. The shame of that would haunt Tigerkit later on in life, and without a father in his life, he was left vulnerable to his future mentor's policies. When he was an apprentice, he was mentored by Thistleclaw, a warrior who was well known for his courage and loyalty, but was also secretly training in the Place of No Stars. Tigerpaw learned from that aggression, and one day on patrol assaulted an innocent kitten named Tiny, who was severly injured before Bluestar (then Bluefur) stopped him. That little kittypet would later become Scourge, leader of BloodClan, and then somewhat ironically, Tigerstar's murderer
He was one of the greatest warriors in ThunderClan when then Firepaw (later Fireheart) first joined. He was believed to be deathly loyal and devoted to the Clan's well-being. However Ravenpaw had seen him kill ThunderClan's former deputy, Redtail in hopes of becoming deputy. Ravenpaw confessed what he saw to Firepaw, and later escaped ThunderClan to stay safe.
Once made deputy, Tigerclaw desired promotion, and set a trap for Bluestar, ThunderClan's leader at the time, to be hit on the Thunderpath. Fireheart's apprentice Cinderpaw (later Cinderpelt) was caught in it instead, and was permanently crippled.
After that plan failed, he plotted with Brokenstar to lead a team of rogues into ThunderClan camp so that while the Clan was distracted, he could kill Bluestar and blame it on a rogue instead. Fireheart saves Bluestar in time, and then Tigerclaw is sentenced to exile, while Fireheart replaces him as deputy.
For the majority of the next book, he is seen as a rogue, sometimes prowling ThunderClan's territory, and slaughtered one of their Warriors, Runningwind.
Soon, opportunity to become leader presented itself. ShadowClan was left leaderless after their leader Nightstar, and their deputy, Cinderfur, died from a sickness eidemic. He was appointed leader in their place, and then given nine lives at the Moonstone; A life for compassion, given by Littlebird; A life for training young cats wisely, given by Badgerfang; A life given by Pinestar to understand what goes on beyond the border; A life for knowing that size isn't everything, and that he should beware small cats (foreshadowing his death at the claws of Scourge); A life for pride and knowing that a Clan can stand alone, given by Sedgestar; A gift for placing faith in StarClan; A gift for trusting your instincts given by Redscar; A life for mercy given by Mossheart; A life for farsightedness, which was given by Cedarstar.
Now known as Tigerstar, he attempted to get revenge against ThunderClan by setting a pack of dogs onto ThunderClan territory. This lead to the apprentice Swiftpaw dying and Brightpaw being permanently scarred. He then lay a trail of dead rabbits to ThunderClan camp, that ended with the queen, Brindleface, he slaughtered so that the dogs would get a taste for cat blood. His plan was thwarted when Fireheart broke the trail and then lured the dogs to the gorge. At the gorge, before Fireheart could lead them over, Tigerstar attacked Fireheart to let the dogs catch up and kill him.
Bluestar sacrifices her last life to save Fireheart by cannoning herself on the dog's side, thus throwing both herself and the dog over the gorge and into the river. Bluestar is pulled out by the RiverClan warriors Mistyfoot and Stonefur. Tigerstar looks on as Bluestar begs the two RiverClan warriors for forgiveness, revealing that she is their real mother. He watches as Bluestar dies, leaving his arch-enemy Fireheart in control of ThunderClan, to become Firestar.
Later, Tigerstar announces his plan to unite the forest under his rule as one Clan, saying that it was "StarClan's will." This was received negatively, except by Leopardstar, leader of RiverClan, who had already allied with him and to create "TigerClan." He led an era of terror , persecuting and killing half-Clan cats. This persecution led to the death of the half RiverClan, half ThunderClan, Stonefur, who was Leopardstar's loyal deputy. He was slaughtered by Tigerstar's deputy, Blackfoot, and Darkstripe, while defending the half-Clan apprentices Stormpaw and Featherpaw. Firestar, Graystripe, and Ravenpaw (Tigerstar's former apprentice), saved the three remaining three hostages, Stormpaw, Featherpaw and Mistyfoot and allowed them to stay in ThunderClan.
He tried to get WindClan to join him under TigerClan, and so he launched an attack on the WindClan camp to instill fear, and left a message to meet him at Fourtrees the next day.
Tigerstar met with Firestar and Tallstar, WindClan's leader, to hear their answer on whether or not they would join TigerClan, which they both refused. He then offered a position especially to Bramblepaw, his son, and Firestar's apprentice. Even though Bramblepaw's sister, Tawnypaw, left ThunderClan to join TigerClan on her free own will, Bramblepaw declares that he'd rather die than join his father. In response, Tigerstar reveals BloodClan, a gang of rogues from Twolegplace who are led by the small black cat Scourge. Firestar attempts to convince BloodClan of Tigerstar's treachery, telling them Tigerstar's history and that though Tigerstar had offered the group part of the forest it was unlikely Tigerstar would hold up his end of the deal. Tigerstar tells them to disregard this and orders an attack, but as BloodClan only listens to Scourge, they refuse to attack. Scourge decides that there will be no battle that day. Tigerstar accused Scourge of being a traitor and tried to kill him; however, Scourge ripped Tigerstar open from throat, through his belly, and to the edge of his tail. Tigerstar lost all nine lives at once, putting what seemed to be the end of the most dangerous cat in the whole forest.
Tigerstar's hatred lived beyond death, though. In the next arc, he waked in the Place of No Stars, also known as the Dark Forest, plotting revenge against Firestar. He discovered that he could dwell in the dreams of others, and began training his sons Brambleclaw and Hawkfrost in their sleep. Later on, Hawkfrost sets a trap to kill Firestar, but Brambleclaw saves his leader and kills his brother instead. Once dead, Hawkfrost resumed training with his father, eventually training more Dark Forest cats to one day wage war against the Clans.
Tigerstar then began to influence Lionblaze, whom he believed was Brambleclaw's son. Lionblaze turned on Tigerstar when he learned that Tigerstar only wanted revenge against ThunderClan, instead of making Lionblaze a better warrior like he promised.
In the final book of Omen of the Stars, the Last Hope, Tigerstar unleashed the Dark Forest Cats he had been training to attack the Clans. Near the end of the war, Tigerstar faced off against Firestar. They consecutively kill each other, sending Firestar to StarClan, and destroying Tigerstar's spirit for good.
- Tigerstar's death is extremely similar to that of Claudandus. Both are cats who have their stomachs ripped open in a fight, the only difference being Tigerstar was slain by a villain.