Cracked Arcane Eggひび割れた神秘術のタマゴ

A luminescent egg that is about to hatch.
In-game description

How to use Cracked Arcane Egg

Cracked Arcane Egg is a pet egg that is about to hatch. Using it hatches Arcane Symbiote.

Hold Cracked Arcane Egg and use it (right-click).
Arcane Symbiote hatches. Put it in the pet slot of your equipment to have it fight with you.

You get it by putting Arcane Egg into an Egg Incubator with electricity connected. One egg takes 30 minutes (the crafting time in the game data is 1,800 seconds). If the power goes out, incubation pauses and continues when power returns; taking the egg out resets the progress.

Cracked Arcane Egg key points (from the game data)

Sells to merchants for 7 Ancient Coins.

Calculated and summarized by this site from the game data (1.3.0.6).

How to craft Cracked Arcane Egg (materials)

Crafted at Egg Incubator What each crafting station makes →

Material	Amount	How to get the material
Arcane Egg	× 1	Enemy Chest

Crafting time: 1,800 s