An Upper Darby, PA woman has been accused of biting off her mother's thumb and possibly eating it during a  fight inside of a bathtub. 21-year-old Kristie L. Foley was found at her sister's home on Wednesday night, three days after the attack. According to authorities, Foley bit her mother several times times at the apartment they share following an argument.

Police Superintendent Michael Chitwood called it "domestic cannibalism." "We never found the tip of the finger. We don't know whether she ate it or swallowed it. Totally out of control. We don't know if she was high on drugs or what." Chitwood added that Foley also bit her mother's hands and legs. 

The unidentified 42-year-old woman was taken to University of Pennsylvania Hospital, where she's in serious condition with multiple bite wounds. Foley, who was charged with assault and harassment, was arraigned on Thursday. She's being held on $20,000 bond.

[via NY Daily News]