Planet Destroyer | Universe Savior | Cute Creature
Mooncake is a new species of alien originally discovered by the Scarlet Lance fleet near a star about to go supernova. His discovery prompted the destruction of the Scarlet Lance by the Lord Commander after the ship refused to give him up. The Lord Commander subsequently began hunting him before the Final Space series begins.
When Gary finds him at the start of the series, he names Mooncake after a childhood pet; a caterpillar given to him by his father, John Goodspeed, before he passed on in front of his son and the caterpillar. During chapter 8, it is shown that when the energy wave and the antimatter blast closed final space, Mooncake was created.