Olga is a female anthropomorphic duck.
Olga was hired by Scrooge McDuck as his new secretary for his magazine, after the former one, Simone Cido, was revealed as an undercover manipulative criminal.
Olga is a judo and karate champion, and it's possible he hired her on these merits, ensuring a level of security to his office. As soon as he introduced her to Donald and Fethry, they immediately tried to woo her, as they did with Simone.
When Duckburg was attacked by Zlana van Hydroolik's clone monsters, Olga was one of the citizens who rose to defend the city, taking on a characteristic pose showing she was ready to use her martial arts skills to do damage.
Olga first appeared in the Brazilian Uma Patinha na Patada comic story, originally published in March 1985.