The Galactic Grandma (銀河の祖母, Ginga no Sobo) is a former self-claimed clairvoyant and a fraudster, now an incarcerated convict.
Yorknew City arc
The Galactic Grandma was mentioned when Neon was talking with Chrollo about what inspired her ability. The Galactic Grandma once said, "Predictions exist to to help living beings achieve happiness." And further states, "This is the reason why I only choose to only predict bad news. So people do their best, so it doesn't happen." Although several years later, she was later convicted of fraud and was arrested. It's also said she doesn't believe in the afterlife.