The Animorphs Sanctuary was a fan club that Animorphs readers could join through Scholastic from January 1, 1999 through April 30, 1999. The reader would receive an introductory pack with gifts, 3 subsequent newsletters, and through those mailings a total of three secret codes which would allow access to view content on special parts of the scholastic.com/animorphs web site. The introductory pack consisted of an Animorphs amulet/necklace with the "A" logo, an Animorphs Sanctuary official passport and poster, the first newsletter, all inside a black folder sealed with an "A" logo sticker.
The subsequent 3 mailings each contained a newsletter in the form of an AOL-style "chat" among the Animorphs members, ending with a new special password to access the Animorphs Sanctuary part of the web site. Using these passwords members could access the exclusive Sanctuary Screensavers made by cover artist David Mattingly.