 The script called for Isis, when in cat form, to make various cat  sounds on cue (meows, purrs, growls, etc.) Since finding appropriate  real cat sounds for the soundtrack proved problematic, when the  director discovered that Barbara Babcock (I) (qv), who was hired  to do the voice of the Beta 5 computer, and for a cameo as Isis in  human form anyway, could vocalize convincing cat sounds, Barbara  Babcock was called upon to vocalize Isis cat sounds as well. I note  that in the trivia it recounts how Barbara Babcock was the voice of  the computer, but also has a cameo as "Isis in Human Form"...but in  the credits Victoria Vetri of "When Dinosaurs Ruled the Earth" fame  has the credit...who was it? I havent seen the episode in awhile,  but my recollection is that Isis looked more like Vetri...???