Kigaan

Kigaan was a Youma summoned by Jadeite to drain energy from unsuspecting girls as part of the Dark Kingdom's continuing energy-gathering efforts. She appeared in anime episode 10. In her true Youma form, she was a female humanoid with brown/green skin and long red hair.

She masqueraded as the driver of the bus that stopped near the Hikawa Shrine. She first appeared to be a stern-looking bus driver with her hat pulled low over her eyes. The bus that she drove was meant to collect the girls who had come from the shrine, where they had purchased charms, but the charms had been cursed by Jadeite, and sapped the girls' energy.

The girls would then get on the bus, which Kigaan would drive into another dimension where the girls' energy was collected. After first being too scared to get on the bus due to Kigaan's scary appearance, Usagi disguised herself as a bus attendant and boarded the same bus with Luna the next day. Once on board, she discovered that the girls had all fallen unconscious. She told the driver to stop, but was instead transported to the other dimension with the rest of the girls.

After being kicked off into the new space, Usagi watched as Kigaan lept out of the bus, just as Rei was sent toppling through a portal into the dimension by Jadeite. Kigaan caught her before changing to her true appearance. Usagi transformed into Sailor Moon and attacked Kigaan with her tiara, but Kigaan jumped out of the way while holding Rei in a head lock. Phobos and Deimos, who had been pulled through the same portal as Rei, then attacked Kigaan, forcing her to let go of Rei. Sailor Moon's tiara circled back and Kigaan caught it easily, only to have it trap her by creating a tight ring around her arms and torso. After squeezing out of it, Kigaan was killed when Sailor Mars used Fire Soul against her.

(Source: Project WikiMoon)