The chocolate egg was a reward from the 2008 Easter event. To get into the burrow to do the event, the player had to collect three eggs and give them to the guard bunny. After completing the main event, and obtaining the chocatrice cape and Bunny Hop emote, the player could optionally receive chocolate eggs by collecting additional chocolate chunks and placing them into the mixer. To get all of the prizes, (the chocatrice cape, bunnyhop emote, and three chocolate eggs), you needed a total of 40 chocolate chunks. Up to three eggs could be obtained, after eight, six, and four chunks of chocolate, respectively.
Several versions existed:
The eggs healed ten LP upon eating, and gave the message: "You eat the egg and get chocolate all round your mouth. It heals some health, though."
Attempting to alchemise the egg gave the message: "You doubt the Easter Bunny would be impressed if you turned that to gold." On 31 March 2008 all chocolate eggs melted and turned to chocolate dust. Players holding chocolate eggs in their banks received this message upon logging in: "You remember with dismay that you left some chocolate eggs in your bank. They will have crumbled to chocolate dust by now."