Yellowfang's Beginning

The one major thing that came out of Mistystar's Omen was that the first chapter of Yellowfang's Secret was included at the end of the book. It starts out with Yellowfang as a kit, Yellowkit, in the ShadowClan nursery, playing with her siblings, Rowankit and Nutkit. They're bullied by the older kits in the nursery, Raggedkit and Scorchkit. The kits get into a fight when Yellowkit accuses them of being kittypets, as their father was a kittypet. Rowankit and Nutkit, as well as Scorchkit, have not been mentioned in any other books, so it may be assumed that they die sometime during Yellowfang's Secret.

There was also a sneak peek in Enter the Clans that talks about a prophecy predicting that a ShadowClan medicine cat will destroy ThunderClan.

Here is a map of Yellowfang's family tree: