#2 - Jan. 24, 2010, 6:48 p.m.
The authentication key that is used to upgrade an account is also what flags the account so that all characters receive the Collector's Edition pet. Please note that an authentication key can only be used to upgrade a single account, and cannot be transferred from one account to another. Therefore, purchasing a used copy would not be advised.
However, if you are able to locate an unused Collector's Edition authentication key, then you can add it to an account at any time, even if the account has already been upgraded via a standard edition. For example, if you have already upgraded your account to the Burning Crusades with a standard edition key, but you found a Collector’s Edition of the Burning Crusades hidden behind the bargain bin at your local retailer, you could upgrade your account to a collector's edition status by entering the new authentication key on the following page:
https://www.worldofwarcraft.com/account/upgrade-account.html Please note that your standard edition key that you originally upgraded the account with is still considered to be used, and cannot be used to upgrade another account. If you would like to see if that standard edition key can be replaced, then you would need to contact our Billing and Account Services department for assistance. Please note that this option is not guaranteed at this time.
The pets that come with the Collector's Edition are automatically distributed via an in-game mail to all existing characters, and newly created characters on that specific World of Warcraft account.