Before the release of Crookedstar's Promise, a fan suggested a Yellowfang Super Edition, and Vicky replied she was thinking of ideas for the 2012 Super Edition. Now that Super Edition has been announced: Yellowfang's Secret.
When the fifth series was announced, it had no working title yet. Fans began calling it "Dawn of the Clans" because of the way it was described ("We'll be going back in time to the dawn of the forest Clans..."). HarperCollins Children's now lists it with the working title "Warriors: Dawn of the Clans" instead of "Warriors - 5th Arc".
Big Name Fan: Blizz/Blizzardclaw (creator of the largest fansite, and the only fan Vicky has given her email address to).
Development Hell: The online game. Announced in February 2010, they picked beta testers in March 2010, saying that the game would be out at the end of 2010. The beta testers never got another message after the one saying they were picked to be one, nor have the gamemakers made any posts on the official forum to keep fans updated on the game's progress like they promised to, nor have they made any official statements saying whether or not it's cancelled.
Sunrise: Leafpool and Crowfeather are the parents of Hollyleaf, Lionblaze, and Jayfeather.
The Forgotten Warrior: The Voice in the Tunnel is a very-much alive Hollyleaf.
Post Script Season: The Darkest Hour, the sixth book and Grand Finale of the Original Series was originally going to be the last Warriors book. However, the series sold well enough that Harper Collins asked the authors for a new trilogy. The trilogy was later expanded into another full six books, rendering the planned second Grand Finale of the series, Dawn, the middle of the second arc instead. While the authors were writing The New Prophecy, they were contracted for a third arc (which later became two arcs), and so included a myriad of sequel hooks. Vicky actually intended to end things with The Last Hope, a definitive Grand Finale, but Harper Collins requested a fifth series. Vicky decided to write a prequel, Dawn of the Clans, feeling the ending of The Last Hope was conclusive enough. However, due to massive fan demand, Vicky decided to write one last Super Edition taking place after The Last Hope, telling the story of the new leader: Bramblestar's Storm.
Brambleclaw and Sorreltail are based on Cherith Baldry's cats, Bramble and Sorrel.
Sol is based on someone's cat named Aslan.
Millie's appearance is based on a cat owned by one of Vicky's coworkers (she promised to put his cat in the books). The name Millie comes from the fact that he is a fan of the Millwall football (soccer) team.
When first describing some of the stories that would be in Secrets of the Clans, one they mentioned was going to be about "how Fernpaw and Ashpaw really felt about leading the dogs to the gorge". Fans were pretty surprised when it didn't appear in the final version.
There was going to be a field guide (after Battles) called Allegiances of the Clans, about the politcal, friendly, and romantic relationships in the series, but it got cancelled by HarperCollins for unknown reasons (the authors guessed that maybe HC decided that there wasn't enough info to fill a full book.)
Crookedstar's Promise was originally going to be a very different book. Vicky teased that it would involve the reason Crookedstar allowed all the forbidden love between RiverClan and ThunderClan, and asked fans if they thought it could involve a sinister prophecy. Later, the first blurb stated that Crookedstar would "receive a prophecy that he would be utterly betrayed by everyone close to him". Kate also mentioned on her blog that Redtail would be playing some sort of role in the book. None of these things appear in the final version.
Cats of the Clans was written entirely in one day by Vicky. The book is dedicated to her niece, who was born that day.
Illustrator Don Hudson had some interesting revisions he had to make, which he talked about on his blog. First of all, there was the dead rabbit that he had to turn around because even a bloodless, clean dead bunny looked too creepy, as described under Bloodless Carnage on the main page. There was also a moment in the third volume where the kits find an abandoned Twoleg nest to shelter in, and there happens to be a car in the yard. The editors left a note on the page◊ saying "If these marks on car are indicating rust, all good; if bullet holes, please remove." Don asked readers if they thought it was rust or bullet holes, and one commented that they look like bullet holes, judging by the fact that cars tend to rust from the bottom up. Don agreed, and removed the marks.
You know that cat in the center of Night Whispers, that the authors say is Flametail? That was originally meant to be Ivypaw on the cover of Fading Echoes. Kate posted the original cover◊ on her blog, saying here's the cover, but Ivypaw's the wrong color, so it will probably be changed. (She removed that line from the post within a day, because that was before Sunrise came out, and nobody knew who Ivypaw was.)
In early drafts of Into the Wild, Bluestar's name was Moonstar. When they were to mention her warrior name in Forest of Secrets, it was going to be Bluestone, but they thought it sounded too much like "Moonstone". Tigerclaw's name in Into the Wild was Hammerclaw, until very late drafts, when someone pointed out that cats don't know what hammers are.
Pretty much the only idea suggested by a fan that they've actually used in the books is Thistleclaw being Snowfur's mate; it was suggested in a Wands and Worlds chat right before they were writing Bluestar's Prophecy, and Vicky really liked the idea.
There was one tour Vicky was on while they were still writing Bluestar's Prophecy. At one event, a fan said something about how Whitestorm is Bluestar's nephew. Vicky was surprised. "Where does it say that in the books?" The crowd answered: "Secrets of the Clans." Vicky said that she'd have to change Bluestar's Prophecy to reflect that fact, because she'd originally had Whitestorm born a moon after Bluestar.
When writing The Last Hope, Kate Cary realized at the last minute that she'd forgotten to put Lilykit and Seedkit into the book. She had to quickly add them into the book two days before it was sent to print.
In The Last Hope, Firestar's death seems random and unclear. Kate explained it on her blog:
It wasn’t the tree that killed Firestar. He died of his wounds. Dovewing only imagined she saw him get up and walk away. The lightening [sic] and the flaming branch just brought her back to reality.
Most typos in the books appear in all versions. However, there is a rare error that appears in only some editions of Into the Wild: when they're heading toward Highstones, it says, "Yes," replied Graypaw. "It runs up from ShadowClam territory." The books with this typo have been referred to as "ShadowClam copies".
When I first got the character outlines, Millie was just described as a tabby. Due to the tight schedule, I had to illustrate the first book's cover before I had even received the script. There are 2 color versions of The Lost Warrior cover- one in daylight and one that is later at night. The editors decided to go with the darker cover so it's hard to see what color Millie is. However it was already established in my mind that she was a rosy brown tabby. I didn't find out that she was described as silver until 8 months later when she first appeared in the novels. At that point, I had already drawn and colored the cover of Warriors Refuge where she is obviously a a brown tabby. I asked my editor at Tokyopop if I should change her color but we decided that it would look dull to have two gray cats side by side. So, maybe Millie is a rose tinted silver tabby? Besides, it is a comic and hair/fur is often outrageously colored in manga!
Parentage of some cats which wasn't revealed in the books:
Firestar's parents are Jake (from Bluestar's Prophecy) and Nutmeg (a never-seen kittypet mentioned in the official app).
Sandstorm's parents are Redtail and Brindleface.
Dustpelt and Ravenpaw's parents are Fuzzypelt and Robinwing.
Graystripe's parents are Willowpelt and Patchpelt. (She didn't realize that they were brother and sister - she'd made these lineages based on the official site's family trees [which were not by an Erin] to keep things consistent, but had forgotten that they were both kits of Swiftbreeze and Adderfang)
Longtail's parents are Robinwing and Patchpelt.
Darkstripe's parents are Willowpelt and Tawnyspots.
Cats whose appearance isn't described in the books but the authors have said:
The kits at the end of Crookedstar's Promise: Vixenkit is black and Grasskit is a brown striped tabby.
Amberkit, Dewkit, and Snowkit from The Last Hope all have amber eyes. Snowkit is white, Dewkit is gray, and Amberkit is gray with white paws and a white muzzle and one white ear (right ear).
Rowanberry from Yellowfang's Secret is cream and brown with amber eyes.
Mistystar's kits, who appeared in Mistystar's Omen: Primrosepaw is very pale creamy-brown with white paws, and Pikepaw is dark gray with mottled dark markings like a fish.
Leopardstar lost her last lives because of feline diabetes.
Vicky once said that SkyClan left the forest about twenty years before Into the Wild began, and the Clans formed about twenty years before that. However, as this was a long time ago, before they delved too deeply into the Clans' past, it may no longer be accurate.
Jake was killed by a meteor while sitting on the fence. (Okay, this one is probably a joke, but it really should be canon.)