The rebirth is an event in the final days of the Divine Order and League of 20,000 Planets, following the completion of the Cleansing. The purpose of the rebirth is to return the insect essence to the now fully restored Giga Shadow, survivor of the Insect Species, at which point it may proceed to subjugate and eradicate the severely crippled human race, to rule the entire Light Universe.
In Lexx 1.4 Giga Shadow the events of the rebirth are shown as a ceremony performed by the high priests of the Divine Order, the last living people on the Cluster. There they prepare the brain of His Divine Shadow, and current vessel of the insect essence to ascend on a pillar to an orifice in the Giga Shadow's exterior where the essence may return to the gigantic insect. Events are interrupted however when in the final stage, where the priests are supposed to simultaneously kill one-another, Yottskry survives and attempts to prevent the rebirth from completing. The priests are all killed, and the brain falls from the pillar, seemingly preventing the rebirth from occurring.
However, shortly after the crew of the Lexx return to the Cluster, protoblood from the Giga Shadow's orifice reanimates Yottskry, who then becomes an unwilling host to the insect essence. After eventually losing his struggle with the insect essence he is absorbed into the Giga Shadow's brain directly, returning its essence and completing the rebirth, reawakening the Giga Shadow and freeing it to emerge from the Cluster.