Chocolate Easter Eggs are items that can be purchased on Easter Event. These always makes you pet full (since on real life chocolate easter eggs full us too),but the Fiufius one is a bit more rarer.
Rarity of the items
Christine de Flu: Uncommon
Fiufius: Slighty Rare
Where to Buy
You can buy a Chocolate Easter Egg in the shop "Supermarket" at the Shops page on the site. Though the Fiufius egg is free and everybody will get one on event ending.
Get a Free Toy
Send a message to TwilightTwily saying that you have given the item to your pet for eat,and say which character you have given (Fiufius,Marzipan or Christine).
And you can also PM the code "EasterEggToy" (caps does not matter) and then PM one of the characters:
Note that you must have given the egg for your pet!