Each egg contains within it the soul of a Mythic that will be set free by the flames of the Odd God’s Hearth.
There are three types of egg: Legendary, Runic, and Stone. A Legendary Egg can spawn three Mythic forms; it will be down to the minter to decide which form their Mythic will take. A Runic Egg has two potential forms, and a Stone Egg only one.
Your odds of getting a Legendary Egg will decrease the later you claim your egg. Eggs claimed within the first week of the first Diamond Nest being hit have the highest chance of a Legendary Egg (60%; rest are Runic). Those claimed after the first week within the first month also have better odds (40% Legendary; 60% Runic). Thereafter you are more likely to receive a humble Stone egg (20% Legendary; 60% Runic; 20% Stone).