The blind, yet strong-willed leader of the Thunderians, the race of humanoid cat-people who inhabited the planet Thundera before it was destroyed in a terrible cataclysm. Although a few Thundercats escaped, Claudis stayed behind to help guide their ship while it fled from Thundera. Claudis' son, Lion-O, is one of the Thundercats who escaped on the ship to Third Earth. Lion-O is now the leader of the Thundercats.