Metins from level 40 have a drop chance of about 25%.
Metins from level 65 have a drop chance of about 45%.
Metins from level 90 have a drop chance of 65%.
Which easter egg can be dropped is completely random.
Additionally, a hidden egg drops from the Metin stones.
The following items can be obtained from Hidden Egg:

Golden Easter Egg

Sweets
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The following items can be dropped from all bosses:
Power of Spring (Crafting Item)
Empty Basket
Easter Stone
Golden Easter egg
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