Fly, to Our Friends! - S2.E36

After hearing the truth about their mission, Happy and Charle run away from the kingdom and end up with two mysterious cats, Lucky and Marl, who's egg had been taken by the queen to be used in the Dragon's Slayer Extermination Project. And Happy and Charle's hearts have been shaken by the kingdom and by what they think they had done. Will Happy and Charle find strength within their own hearts to go save their friends? It is implied that Lucky and Marl are actually Happy's parents.