Initial Egg
From HorizonXI Wiki
These special eggs which have an initial inscribed on them are handed out by the Moogles that appear during the Egg Hunt Egg-stravaganza events. They can also be dug up using a Pickaxe at a Mining Point, by logging, excavating or harvesting anytime throughout the year.
Unlike normal Bird Eggs these cannot be eaten or crafted and cannot be sent to other players through the Delivery Box. They can be stored in stacks of up to 12 of the same initial.
List of the Initial Eggs
Only the 26 letters of the latin alphabet are used.