Extra Rare Egg (also called Premium Egg in Season 1) can be bought for 20 Crystals from the Get Pets page. This kind of egg will hatch an A or S grade Pet. You will also receive 66 gift points for each purchase. You may receive an upgrade of a Pet you already own, if it's not at level 8 yet, so it is recommended that you upgrade all your pets to Level 8 in order not to waste any precious Crystals. This is the only pet egg that does not contain coins, so if you have all Pets at max level, you will not be able to hatch any more eggs (the Hatch button will be disabled). Alternatively, players are able to obtain a free Extra Rare Egg from the Invite Event.
List of Pets obtainable or upgradeable from Extra Rare Egg Edit