Cassiopeia's hair was black as night and she had paper-like skin. Many say she was very alike her great-aunt Elladora Black.
Cassiopeia was smart, arrogant and extremely materialistic, but had a soft spot for children.
Cassiopeia attended Hogwarts from 1926 to 1933 in Slytherin House. She shared a dorm and friendship with her cousin Callidora Black. She passed all her O.W.L's and N.E.W.T's and finished her education with outstanding marks in 1933.
Cassiopeia never married or had any issue.