The excellent Autodesk product and resource for tips and tricks website CAD Forum has divulged details on the AutoCAD 2005 Easter Egg.
Easter eggs are the practice and long-standing tradition of software developers to add a little something special in the program such as listing team members for the project. Just like the Easter tradition of locating a surprise or a hidden egg also known as the Easter egg hunt. The Easter eggs are hidden and take some work to locate the sequence to activate making it also fun for some to locate and we have had informal contests in locating them in the past. In most cases, at least here at Autodesk the Easter egg development of the Easter egg does not take away from regular development work and the Easter eggs are developed usually in a short time and after hours so they do not effect the scheduled software development. For the last few releases, the Easter eggs have even listed top beta site customers as well.
Link to CAD Forums details on the AutoCAD 2005 Easter Egg Click Here