Not that specifically. But there is a non-d20 RPG titled Cartoon Action Hour that is built around the premise of most retro 1980's saturday morning cartoon and live-action shows.
BTW, who owns the Thundercats intellectual property?
In my sig there is a link to a free preview of a mummy template I wrote for Gaming Frontiers: Monsters. It was loosely inspired by Mum-Ra. It is 3.0 but conversion to 3.5 is easy just change the DR to 3.5 standards.