Squirrelflight

Warrior of ThunderClan, and one of the main protagonists of the The New Prophecy arc, as she tags along on the StarClan-chosen journey to the sun-drown-place in order to find the Clans a new home, just because she wants to and she can. She is described as a dark ginger she-cat (just like her father, Firestar) with a plumy tail like a squirrel. We get her point of view in the books Dawn and Twilight.

From the moment she appears in the books, Squirrelflight is characterized as brash, outspoken, headstrong, brave, and extremely close to her medicine cat sister Leafpool. Her future mate, Brambleclaw, finds her incredibly annoying, but also feels a certain chemistry with her from the very beginning. Though Squirrelflight is clearly destined to be with Brambleclaw (who is ironically the son of her father's greatest enemy, Tigerstar), her romantic issues with him are a source of great conflict in her life. Their relationship blossoms on their shared aforementioned journey to the sun-drown-place amidst much bonding through quarrelling, but just when it seems they are about to get serious, Squirrelflight gets really mad at Brambleclaw for wanting to spend time with his obviously evil half-brother, Hawkfrost. As a result, she somewhat pursues a relationship with Ashfur, which makes Brambleclaw insanely jealous, and their arguments get vicious. Eventually, though, she realizes through a life-or-death battle with badgers that the two of them are made for each other, and she promptly ends things with Ashfur as gently as she can. (But rest assured, this is not over yet.)

To recap, Squirrelflight is now the mate of Clan deputy Brambleclaw, sister of Clan medicine cat Leafpool, and daughter of Clan leader Firestar. So as you can imagine, her position in the Clan is ironclad, as she's related to pretty much everybody who's important. That means she can severely break the warrior code and not having to worry about getting exiled, or anything like that, right? And break it she does, by pretending she gave birth to her sister's kits in order to save her from social ruin, as medicine cats are not supposed to have kits. This of course gets found out, by none other than Ashfur (remember him?), who tries to burn those kits alive and force her to watch in revenge for her breaking up with him. Alright then.

Through a sequence of plot twists, Ashfur is killed, and the truth about her fake motherhood is revealed at a Gathering by her fake daughter Hollyleaf. Squirrelflight does not really get punished for her lie, other than that she loses her mate and is treated terribly by her adoptive children for a while, but it's all resolved in the end. Brambleclaw takes her back in later books, and Squirrelflight reverts back to her cheerful and optimistic self, a valued member of ThunderClan. Hooray!