Cackling Agatha is an archfey and former beneficiary of Ylldove's demonic patron Xaoc.
She is extremely tall though so hunched that her body resembles a question mark.
She offers Ylldove her patronage to replace Xaoc's as a means of disrupting Xaoc's plans and implies that Ylldove might not be Xaoc's only warlock.
She is rude to apples.