The Royal Flag Ship was the ship the ThunderCats used when they fled Thundera.
History[]
The ship had carried the ThunderCats as Thundera had blown up. It was also attacked by the Mutants, which caused it to crash land on Third Earth. After the ThunderCats got out and had a Cat Lair constructed by the Berbils, Panthro took scraps of the ship and developed the ThunderTank from it.