Susan Silo was born in New York City and began her acting career on television with an appearance on The Jack Benny Show. She later co-starred in the NBC sitcom Harry's Girls and made guest appearances on numerous 1960s TV series, including Route 66 and Sea Hunt. In 1964, Silo appeared in an episode of Jack Palance's The Greatest Show on Earth. She also had a voice-acting career, starting as a talking cow in Land O Lakes Margarine commercials for over ten years. Silo has done voices for Hanna-Barbera, Marvel, Disney, Ruby-Spears, DIC, Film Roman, Murakami Wolf Swenson and others. Some of her famous roles include Wuya the Witch in Xiaolin Showdown, Dr Karbunkle in Biker Mice from Mars, White Queen on Pryde of the X-Men, multiple voices on What A Cartoon, Sue on Pac-Man, and Mama Mousekiwitz in Fievel's American Tails. Silo also voiced characters for video games such as Crash Tag Team Racing and X-Men (arcade game), where she reprised the White Queen. In 2008, she voiced Auntie Roon on The Life and Times of Juniper Lee and Flamestrike in Dragonlance Dragons of Autumn Twilight. In 2009, Silo guest-starred as the cat empress Neferkitty on The Garfield Show, episode "The Curse of the Cat People".