Birchstar is a cat.
In Code of the Clans, Birchstar is an ancient WindClan leader. During a Gathering, they report a new litter of kits in WindClan, and they also mention that WindClan has two new warriors. After Darkstar, SkyClan's leader, proposes that the rule that states the word of a Clan leader is law should be added to the warrior code, Birchstar agrees with him along with other leaders.
Notes and references
- Revealed in Code of the Clans, page 124