Isis is Gary Seven's cat and partner
Isis in human form
Isis was the Pet cat owned by Gary Seven. In 1968 she was involved in the disarming of a nuclear bomb. She was more than she initially appeared to be. Exactly what she was remains a mystery. Evidently, she was capable of understanding Gary Seven, and of communicating with him in at least a rudimentary fashion, and she accompanied him wherever he went. Isis was also able to take human form. (TOS: Assignment: Earth)