Eggomancy

This spell transforms a creature or object that you can see within range into a chicken egg. An unwilling creature must make a Wisdom saving throw to avoid the permanent effect. The spell has no effect on a shapechanger or a creature with 0 hit points. A willing creature automatically succeeds the saving throw

The transformation lasts for 21 (3d6+3) if the target succeeds the saving throw, afterwards it will hatch to its form the way it was when the spell was cast. If the egg is thrown, the creature within the egg must make a constitution saving throw matching the strength of the thrower. Upon success, the creature will break out of the shell, and take 2d4 damage. If they fail, they die. If the creature fails the saving throw, they are turned into the egg permanently, but can be restored to their original form through greater restoration. If the egg breaks in this state, they die

A creature who has willingly been transformed or succeeds the saving throw can talk and hear while being the egg, and the egg is indistinguishable from any other egg, including all spells and checks to determine otherwise. The egg can roll 1 ft per turn if they roll a 15 or above with strength. If they have not been transformed willingly and failed the saving throw, they can only hear. 

If the egg is reanimated with another spell, a chicken will hatch from it in 21 days.

The target's gear melds into the new form. The creature can't activate, use, wield, or otherwise benefit from any of its equipment.