Yvonne Craig, the performer best known as Batgirl in the 1960s TV series “Batman,” died on Monday at her house in Pacific Palisades, Calif. She was 78.The cause was complications of cancer, her family announced on her web site.

Ms. Craig’s family said that she had breast cancer, which eventually metastasized to her liver, for more than two years, but that she had kept her state private.

Ms. Craig’s Batgirl, who was covertly the daughter of Police Commissioner Gordon, added a scrappy girl-power component to “Batman,” a campy show based on the long-running comic book whose only other prominent female character was the slithery, hot villain Catwoman, played first by Julie Newmar and then by Eartha Kitt.

Batgirl’s flash of purple and yellowish contrasted using the caped crusader’s dark picture.

Before she began her TV career, Ms. Craig was a ballet dancer and traveled with the Ballet Russe de Monte Carlo as the group’s youngest member.

In one of her more memorable television characters, Ms. Craig played Marta, a green-skinned slave girl, in the original Star Trek series episode “Whom Gods Destroy.” She performed an alluring, free-limbed dance that looked to almost overwhelm William Shatner’s red-blooded Captain Kirk, and which Leonard Nimoy’s Mr. Spock pronounced “Mildly interesting.”

Yvonne Joyce Craig was born on May 16, 1937, in Taylorville, Ill.She wrote a book, “From Ballet to the Batcave and Beyond,” in 2000.

She started a job as a real-estate broker, but from 2009 to 2011 she supplied the voice of the character Grandma character on the Nickelodeon cartoon series “Olivia.

Yvonne Craig