Duchess Rowena (Catherine O'Hara) is the main antagonist from Barbie in The 12 Dancing Princesses. She is the cousin of King Randolph. She has insidious plans for the kingdom, but she can't implement them.
Rowena appears in the kingdom by request of her cousin, King Randolph. He wanted Rowena to teach his daughters etiquette after hearing that his daughters were not fit to be "proper princesses". But Rowena forced the princesses to work hard, and in the same time slowly poison the king.
When the princesses went to the magical pavilion, she told the king, that the princesses had left him, but she herself had closed them in the pavilion, and told Desmond to break the magical stones. After, the king made Rowena a queen, and she told him all her plans.
The King almost died, and Rowena became the queen. But, in the castle all princesses appear and expose Rowena. She tried to keep herself safe, and with a magical flower, which she had taken in the golden pavilion, wished "for armor to protect the queen" which causes two suits of armer in the room to come to life and attack Genevieve and Derek. After Derek defeats the suits of armor Rowena uses a second magical flower to wish that Genevieve would keep dancing for ever. And Genevieve, with help of a fan, sent the golden pollen back to Rowena. Rowena then starts to dance and cannot stop when her servant Desmond, tries to help her but he becomes affected as soon as he touches her. They leave the kingdom cursed to dance together fovever, with Brutis in pursuit
It was implied that she wanted (and needed) to take over the kingdom because she was struggling financially. Her carriage was in shambles, the trader told Derek that she never paid her bills and the fact that she had to sell Queen Isabella's silver goblet to pay for the poison she was using on King Randolph.
Rowena shown as true antagonist: she categorically doesn't like dances and music; she has a cold, cruel and proud character. At the same time, she's ready to do anything, if it is for her win. She stole Queen Isabella's goblet, to pay the trader. Also she doesn't like her servant Desmond, but likes her monkey, Brutus,very much.
Rowena has gray hair and light blue eyes. She wears a lot of jewelry, and all of them are made of a cold, blue-green stone. Her dress is also in light-blue color and has a very big skirt. She doesn't like bright colors and forces the princesses to wear gray dresses.
Rowena dresses in an 18-century style costume.