Its really easy- just two simple steps!
Step 1: Find a dragon that you want out of all the available dragons. (You may make your own for people to adopt or make one for yourself if you wish. If you make one yourself, please put a note saying whether it is for you or other people. You may also make your own species and such.)
Notes: If it is for you the staff will move it to your archive. If it is for other people they will move it to the top post of the thread you are on.
Step 2. Copy and paste that dragon's bio into a post of your own on the same thread validating that you want that dragon. The staff will then remove it from the top post of that thread and move it to your archive.
PS: If you no longer want a dragon, simply PM the staff about it, and theyll do the rest! *Delete it, of course.*