Bertie (Sailor Moon)
Bertie, is one of the Negamoon Sisters who work for Rubeus and is the youngest of the sisters. She attacks using dark water that can freeze things.

She is the first one sent by Rubeus to take over crystal points in Tokyo. She sent two droids named Droido and Frosty, but both were destroyed by Sailor Moon.

When the Sailor Scouts fought Rubeus and the Negamoon Sisters, Bertie fought Sailor Venus .

After Catzi turned good, Bertie entered a chess tournament in an attempt to take over the crystal point located there, but lost to Mina in the final round. She entered a "freeze play' game with her, freezing her every time she lost a piece, but Tuxedo Mask broke the spell. When Avery  and Prizma told her that Rubeus would no longer need her, she attempted to freeze herself, but Catzi stopped her and she decided to turn good, Sailor Moon healing her with Moon Crystal Healing Activation.