Granny

Morgantha, more commonly known by locals as "Granny", took on the appearance of a sweet old lady and was often found slowly walking the streets of Barovia's settlements selling pies from her cart. However "Granny" was actually a fearsome night hag that lived in the windmill east of Vallaki with her two night hag daughters, Ophelia and Bella.

Granny was known for selling Granny's Dream Pies which contained children and caused people to become horribly addicted, to the point of selling their children to be able to afford more.

History
The party of Hallgrimm Mikkenson, Sigismund the "Bold", and Narid Ashplantt first encountered Granny in Barovia village on the morning they were to set off to Vallaki for the first time. Hallgrimm happily purchased from her and waxed lyrical about the taste of a pie. In subsequent nights he had vivid and pleasant dreams.

She was again seen in Vallaki on the day of the Feast, again selling pies from her cart.

When the party sought the assistance of Jenny Greenteeth in having their curses removed she bargained with them that she would do this if they brought her the heads of the three hags living in the windmill. The party attacked the windmill but were defeated by the night hags. They were shown mercy, with Granny even removing some of the physical aspects of Narid's curse from him (along with, unbeknownst to him, Felix's cursed tin locket which he had kept on his person.)

After Eklyre Temere accidentally opened a portal to the Nine Hells five flying devil scouts came through and took off searching for a demon. They appear to have battled Granny and her daughters at the windmill and been defeated, with two of them seeming to be unaccounted for and potentially taken captive by the hags.

After coming to learn that children were being killed and put into the Dream Pies the party of Hallgrimm, Narid, and Eklyre staged a second attack on the windmill, this time coming out victorious and killing all of the hags and taking their heads as proof.

Granny's Dream Pies
Granny's Dream Pies are famous across Barovia, able to give the eater fantastically realistic dreams where they complete their wildest fantasies. However the withdrawal effect of not eating a Dream Pie for some time is that those dreams turn into restless nightmares, driving one to exhaustion. Father Lucien advised that often people of Vallaki will come to the Church of St Andral to pray for their loved ones afflicted by addiction to the pies, and suggested weaning off them over time may be possible.

Strahd von Zarovich showed the party of Hallgrimm, Narid, and Eklyre Temere a vision of Granny murdering children to put into the pies.