Katie: Come on, she's a doll!
Henry: Yeah she's a doll like Chucky's a doll.
Henry is referencing the horror character Chucky whose origin comes from Charles Lee Ray, the notorious "Lakeshore Strangler", who is wounded and collapses into a pile of Good Guy dolls. He uses voodoo to transfer his soul into one of the dolls. And thus spawns a series of horror films, "Child's play"