Series 13 of the Treasure Book was released on April 5, 2011. It could have been accessed by entering a single-use unique code from real-life series 13 merchandise into the Unlock Items Online page. Each code entered allowed the player to select any two clothing items from this series of the Treasure Book to redeem for their account. Any color of puffle up to orange could be adopted as well (if the player did not already own the maximum amount of puffles), and adopting a puffle counted as one item.
The clothing items redeemed from the Treasure Book were all their "unlockable" versions (signified on their icon with an opened padlock inside a blue circle), and these versions could be freely worn even without membership. Any color of puffle adopted could be interacted with and walked without membership was well.
On October 4, 2011, series 1 through 13 of the Treasure Book were removed. Since then, if any applicable code was entered into Unlock Items Online, only the most recent series of the Treasure Book was accessed.
Items in the tables that are marked with green backgrounds are items that were first released in this series. This only applies to items that are completely new, not previously existing items with new unlockable versions.
This page contained "Super Exclusives", items which could not be obtained outside of this Treasure Book at the time. The only way to reveal the Super Exclusives page was to access the Treasure Book with codes 5 times.
The Zoot Shoes appear on the Exclusives page despite never being exclusive to the Treasure Book, and were also first released before the Treasure Book existed.
This series and series 5 are the only series, prior to the Treasure Book's restructuring with series 14, in which none of the items that debuted on their Exclusives pages were later available outside the Treasure Book.
