- Mosskit is born to Bluefur along with her littermates, Stonekit and Mistykit.
- Her mother had a forbidden relationship with the RiverClan warrior Oakheart. However, she had a destiny of her own that didn't leave room for a mate or kits. For this reason she was forced to give them up to Oakheart.
- To cover up for her forbidden romance, Thrushpelt pretended he was Mosskit, Mistykit, and Stonekit's father and loved them as they were his own kits.
- Mosskit's mother is Bluestar. 
- Mosskit's father is Oakheart. 
- Mosskit's sister is Mistystar. 
- Mosskit's brother is Stonefur. 
- When Bluestar was bringing Mistykit, Stonekit, and Mosskit to RiverClan, Mosskit does not make it and died from the cold.
- In Secrets of the Clans, it is revealed that Snowfur brings Mosskit to StarClan. She wails and mentions that she wants to stay with Mistykit and Stonekit, and also is slightly scared because Snowfur has stars in her fur.
- She was accidentally called a tom
She is taken care of by Snowfur in StarClan.