Alice series

From Memory Alpha, the free Star Trek reference.

The Alice series was a group of 500 identical androids who inhabited the planet Mudd. They were designed according to Harry Mudd's "exacting" specifications, and was the primary liaison between the vast android population and the crew of the USS Enterprise. (TOS: "I, Mudd")

Alice series #1 - #250 were played by Alyce Andrece, while Alice series #251 - #500 was played by her twin sister, Rhae Andrece.