Medusa (Cassandra is her real name) is a woman in her 17. She owns a big pharmatheutic company, but underneath she is a mad scientist

Her mother abandoned her and her father, a famous scientist who loved her a lot, died when she was 8.

She has dark skin, green eyes and her hair is made of green snakes

She wears a lab coat and safety goggles

She is sadistic and very intelligent. She doesn't seem to care if her test subjects die or suffer. 

However, she still misses her dead father greatly.