Captain Amelia is the experienced captain of the R.L.S. Legacy, the ship Doctor Delbert Doppler hired to journey to Treasure Planet. She is an alien who appears to be some sort of hybrid of cat and woman. She is very beautiful, inhumanly slim, with green, feline eyes, claws that protude through her gloves and exceedingly feline facial features, and can be considered attractive by human standards. She also possesses inhuman agility, a quick wit fuelled by irony, and a British accent. At first she finds Dr. Doppler to be rather stupid but later befriends and even falls in love with him.
Said to be the finest captain in "this or any other galaxy", she is extremely intelligent and independent, intolerant of failure, rudeness, or incompetence of any kind.