2002 Easter event
The Easter eggs are rare because they were only dropped on Easter day. Some people ate them because they healed a fair amount of hitpoints, for something that did not have a considerable price at the time. When players sell Easter eggs, they usually withdraw them in notes as to avoid accidentally clicking an egg, which would lead to it being eaten. It is recommended that when players are dealing with an un-noted Easter egg, that they switch their clicking options from 1-click to 2-click to avoid this issue.
In the past, Easter eggs were worth a small amount of money. However now, prices have increased dramatically to 511,543,047 coins, because of a widespread realisation of the rarity of edibles. Besides for eating, Easter eggs are a symbol of wealth.