The Ghost Elder is a character that you meet in Shantae and the Seven Sirens. Long before the events of the game, a Siren destroyed her ship and drained the life of her crew. She now guards the way to the Boiler.
When Shantae first approaches her, she accuses her of being a Siren, then expresses confusion at Shantae's half-genie nature. She refuses to let Shantae access the Boiler until she proves her worth (by returning a lost Scary Doll to her). To aid Shantae in this inital quest, she gives her a Fusion Stone.
After Shantae has rescued Harmony and defeated the Angler Fish Siren, the Ghost Elder instructs her to visit the Deep Sea Domain for further help. When Shantae returns with the Ghost Genie's choker, the Ghost Elder removes the Fusion Stone attatched to it, then tells her that Harmony ran off to the Mining Site, following strange voices against her advice.
Interestingly, she recognizes the Ghost Genie's choker as genie clothing, rather than a dog collar, before the Ghost Genie reveals herself to Shantae.