Given out in the 2005 Easter event, They were hidden among the avatars in the shop, and could be purchased for 0 cash and 0 gold.
There was no limit on how many you could purchase.
Around that time, many people created a rumor that the eggs will "hatch" into other items.
Softnyx: Sold for a limited time during the Gunbound Birthday Event. From August 16th - August 30th, 2007 you could purchase or gift these items from the Gunbound event page for 4,000 cash each.
ijji (Red Easter Egg Only): Sold for a limited time during the Gunbound Birthday Event. From November 12th - December 3rd, 2008 users could Purchase this item(s) from the Gunbound website for 35 G Coins.
Softnyx (Easter Egg Only): Available for a limited time from December 9th, 2008 - January 6th, 2009, during the 2008 Gunbound Christmas Event. (***Also known as the: "Hey guys lets sell almost every single rare avatar for cash event!!".) This item(s) could be purchased for 2,000 cash in the Gunbound Avatar Shop.
***Unofficial Title.
* Note: The Red Easter Egg has been used 2 times.
** Note: The Easter Egg has been used 3 times.