Mousefur was seen little in the original series, and her personality took a drastic change in The New Prophecy. In the beginning, what we saw of Mousefur proved that she was an independent and free-thinking individual, who had a certain longing for kits that was never addressed. In the late novels of The New Prophecy and Power Of Three her personality reflects that of a very grouchy elder, and she is endlessly challenging Firestar's decisions with her more traditional values. Even so, her personality is displayed such as she expects nothing less then respect from everyone, and she sticks by those who trusts with unwavering loyalty.
HISTORY
INTO THE WILD Listed as ThunderClan warrior: Mousefur
GENERAL
Mousefur has very few lines in the original two series, and it can almost be considered surprising that she survived into the third series. She did - but her new voice in The Power Of Three is no help to Firestar, when she challenges him and rallies the Clan to the question of why he allows so many outsiders within ThunderClan. Mousefur's death can be expected in The Power Of Three, but not before she plays an important part in the moral battle between Clan blood.