|"Ghost girl" is not an official name.|
|Residence||Castle Manor, Elwood City|
|Cartoon debut||"The Fright Stuff"|
During Muffy's party, the girl went downstairs in a "ghost" costume, and accidentally got involved in the boys' prank. She moved Muffy and Francine's tape recorder and glow-in-the-dark balloons to the playroom. She then flew into the library in her costume and vanished, which scared both girls. When Binky showed up in a Cyclops costume, Arthur was bewildered. After asking "Binky, if you just got here... then who is..?" Arthur turned to the girl, and realized that she was a real ghost when he and his friends noticed that she was floating off the ground. They then ran downstairs, frightened.
Later, her father explained to her that although the boy did ask her to help, scaring people is wrong because it hurts their feelings.
Afterwards, she went down with her family in less-scary ghost costumes and joined the party. George complimented on her costume and she said his was cool, too.