Turbo Granny

A yokai who takes the form of a cruel, foul-mouthed elderly woman, Turbo-Granny used to comfort the spirits of girls who died horrible deaths, but started cursing and stealing the genitals of anyone who entered her territory.

After Ayase and Okarun defeat her, Seiko seals her spirit inside a maneki neko doll, and she agrees to aid them for the time being until she can fully regain her powers.

(Source: Dandadan Wiki)