Not much is known about the clan that Mousestar was born in. What is known is that her mother was Berryfur and her father was Flightfeather. Hawkstar, Stormtooth and Sunfur were her littermates. Their apprentice lives were unknown. When they were growing up, her sister fell in love with Ashtail, somebody she used to love, but knew it wasn't meant to be. Instead, she made friend with Braveclaw. It is unknown if Mousecloud had kits with him, as she was seen for long periods in the nursery, though there were no signs of kits. Like her other littermates, Mousecloud was sick of the leaders long reign, so her, her littermates, Hawkflight's mate Ashtail and daughter Rainspirit and Braveclaw tried to kill the leader and deputy, but their plans were thrawted and all seven cats were exiled.
Sparklewing tagged along, putting the new rouge group up to eight members. Despite Mousecloud's desperate attempts to lead the group, her sister Hawkflight took it and changed her name to Hawk. Mousecloud turned her name to Mouse and the others changed their names. She started to get more attracted to Brave and made trouble of herself with the group. Hawkflight's other two children Tigerfoot and Dawnflight and another cat, Hareleap joined the group, putting the group up to eleven members. They made more trouble of themselves until her, Tigerfoot, Dawnflight, Braveclaw and Hareleap seperated from the group and disappeared.
All the members reappeared and formed a new clan. As Braveclaw was leader, the clan was called BraveClan. Mouse and the others changed there names back and the new clan formed. Mousecloud became deputy and did for many moons, until Bravestar lost his last life in battle. Mousecloud became leader after that.
- It is possible that Hareleap is her kit, as his foster mother told the clan that his real mother was wiry light brown, though that described two cats in the clan.
- Mousestar does not hate her sister Hawkstar, though was a bit jealous when she took Ashtail and the lead of the rouge group. She apperantly has the closest bond to her.
- She also knows about her sister's death, but nobody knows that.
- Mousestar may of adgitated the snake that bit Hawkstar, though that is unknown.
A tate for revenge
Mousecloud does not formally appear, but when Hawkstar tells Rainspirit that she wished she let her sister have Ashtail, she is presumably the sister that Hawkstar is talking about as Sunfur never loved Ashtail.
The kits dreams
Although she is not named, she is seen leading her clan to the gathering. She has no speaking lives in the story however.
Mousestar now has speaking lines and is mentioned by name in the story. She is first seen when Featherpaw mistakes her clan for HawkClan, her amber eyes watching her every move. A dead cat is beside her and then she jumps from the rock, which shocks her. She growls at Featherpaw then snarls what she is doing here. When Featherpaw said that had lost her way from HawkClan, she murmers something lowly, then gives a distasteful flick of her tail, then tells her that it's too bad. Featherpaw tries to argue, but Mousestar tells her to leave or she would skin her alive. Featherpaw obeys and leaves back into the forest. Mousestar then says to herself that she should of been kinder because Featherpaw didn't seem to be a bad cat.
Mousestar is late for the gathering, which is rather unusual for her. However, she eventually comes, but she is sick, as she coughs before she speaks. She croaks that the clan has two new warriors named Wetrunner and Sootstorm and announces that the hunting competition is underway.