Boulder

Boulder is a skinny silver -gray tabby tom with a ragged ear and bright blue watchful eyes.

Into the Wild

 * He is a friend and follower of Brokenstar, and is one of the warriors in his circle of "elite warriors." When Firepaw, Yellowfang, Whitestorm, the ShadowClan elders, and a ThunderClan patrol come to rescue the kits stolen from ThunderClan, Firepaw defeats him. He later leaves the camp along with the other elite warriors and Brokenstar. Wetpaw is seen as his apprentice.

Fire and Ice

 * Boulder is now one of Brokenstar's rogues after being exiled. He attacks the ThunderClan camp, following Brokenstar, along with the other rogues.

Forest of Secrets

 * When Tigerclaw leads an attack on ThunderClan, Boulder is a part of the attacking patrol and fights with some of thewarriors.

Rising Storm

 * He, along with Tigerclaw, attacks a ThunderClan patrol near the Thunderpath. Later, he joins ShadowClan when Tigerclaw becomes leader and gains his name Tigerstar.

A Dangerous Path

 * When Tigerstar becomes leader, Boulder is brought back into ShadowClan along with Russetfur, Blackfoot, and Jaggedtooth, who were also part of Brokenstar's group. He is welcomed among ShadowClan.

The Darkest Hour

 * In the prologue, he and Tigerstar go into BloodClan territory so Tigerstar can meet Scourge, the leader of BloodClan. Scourge and Tigerstar form an agreement, and BloodClan comes to the forest.  When Scourge kills Tigerstar, Jaggedtooth joins BloodClan, and Boulder thinks it is worth betraying BloodClan so he can get his claws in Jaggedtooth's fur for betraying him. He fights alongside LionClan, the four Clans combined, led by Firestar to fight BloodClan, then goes back to ShadowClan.

Into the Woods

 * He is introduced by Tigerstar to Sasha, a rogue, as one of his "best fighters". A day after, Sasha comes to the ShadowClan camp, and he, Tigerstar, Oakfur, and Sasha go on a border patrol.  Later, he is planning with Tigerstar and some other warriors near the end of the book.

The Rise of Scourge

 * He is seen with Tigerstar when he is taking him to see Scourge.

Dawn

 * Boulder is now an elder of ShadowClan. When the Clans are deciding where to go, Blackstar says that they will travel to Twolegplace, BloodClan's former home, explaining that one of their elders, Boulder, used to be a member of BloodClan and can show the way and the best hunting places. The other Clans, however, disagree.  When the Clans rescue ShadowClan from the Twoleg monsters, he does not respond to Leafpaw's greeting when she comes to check on him, but sighs softly as she pulls out a splinter in his flank.

The Sight

 * Leafpool gets news from Littlecloud that ShadowClan has lost an elder due to greencough, which could have been Boulder, because he doesn't appear again in the series.

Secrets of the Clans

 * Boulder gives the tour of the ShadowClan forest camp. He talks about the boggy ground, prey and camps of ShadowClan. He takes the reader to the fresh-kill pile. He takes out a frog and says if you take off the skin it tastes like bird and mouse together. He also explains he was a loner before he met a ShadowClan warrior who tempted him into the life of the Clans, not mentioning his ties with BloodClan.

Cats of the Clans

 * Rock tells the kits of StarClan how Boulder was raised in BloodClan, but came to the forest when he heard of how much safer and easier the system of territories, warriors, and patrols sounded. He apparently had too much faith in the Warrior Code. He was the cat who led Tigerstar to Scourge with a desire to impress his new leader, without realizing that he knew from his time in BloodClan that Scourge would never help Tigerstar win a battle and then leave with the promise of some small hunting grounds. According to Rock, Boulder was not an evil cat. His ambition just got the better of him. He thought everything would work out as Tigerstar had planned, with BloodClan helping to take over the forest, and less cats would be hurt if the takeover was smoother.


 * He lived a wretched life in BloodClan, and once he had heard about the forest, he decided to leave BloodClan to live in the forest. He did want to impress his new leader, but he had forgotten about how Scourge could be. He thought that it was better to spill the blood of other cats than their own, especially cats who made his early life a misery.