Kathryn Mullen was a puppeteer for The Dark Crystal performing the female lead, Kira, one of the last in an endangered race called Gelflings. Mullen worked closely with co-director Frank Oz to help develop puppetry styles specific to the needs of the film and also assisted him performing Yoda in The Empire Strikes Back. After starting out with various puppet companies, Mullen began her work with Jim Henson in 1978 as a background performer in The Muppet Movie and became a principal performer on The Muppet Show and in Muppet features. She is perhaps best known for her roles as Mokey Fraggle and Cotterpin Doozer on Henson's Fraggle Rock and performed on The Jim Henson Company's Wubbulous World of Dr. Seuss. Beyond Henson, working with her husband and former Henson art director Michael Frith, Mullen was instrumental in the creation of Between the Lions for PBS. In recent years, also with Frith, Mullen co-founded and serves as artistic director of No Strings, an educational puppet film company whose audience is children faced with conflicts, disasters, and poverty around the world.