Jakoku
Jakoku was a Droid belonging to the Black Moon Clan which appeared in episode 75. He had chalk-white skin with only his arms and part of his face showing, as most of his form was covered with a dark, flowing robe. He carried a scythe which he employed as weapon against the Sailor Senshi.
Jakoku first appeared and attacked Chibiusa in her mind, trapping her in a nightmare. After Sailor Pluto helped the Sailor Senshi enter the child’s mind to assist her, Chibiusa did not recognize them and ran away, at which point the Droid showed himself. When the Senshi transformed and engaged him they found their attacks were simply deflected, and the Droid easily disabled them. Only after Chibiusa asked for Sailor Moon’s help was she able to repel his attack, and she finally destroyed him with Moon Princess Halation.