The Easter Chalice is the chalice from the Easter event, cousin to the God's 
Chalice and 
Sweet Chalice. It is used to summon the boss of the 
Indra Egg Raid to obtain the 
Celestial Egg.
How to get it
Sold by the 
Easter Shop NPC during the Easter event: first collect all 23 eggs, then press the "Secret" button to purchase it for 2,000 
Candy Eggs.
Usage
Throw the chalice into the water: a portal appears, and only the player who spawned it can enter. You are then teleported to a dimension to face the boss (Indra Egg). Once you defeat the boss, you leave with the Celestial Egg.
Easter Gifts
Core Brain
Cup
Cursed Scroll
Dark Fragment
Demonic Wisp
Dinghy
Dinosaur Bones
Disguise Elixir
Dragon Egg
Dragon Koi
Dragon Scale
Dragon Token
Easter Chalice
Ectoplasm
Electric Wing
Empyrean
Enforcer
Fiend
Fire Essence
Fire Feather
Fire Flower
Fish Kebab
Fish Tail
Fist of Darkness