The Brood (1979)

The Brood (1979), the sixth film directed by Canadian king of "body horror" David Cronenberg, stars the dearly departed Oliver Reed as Dr. Raglan, a psychotherapist who has created a means of giving physical manifestation to the negative emotions of his patients in the form of radical, external physical changes. As a result of this treatment, one of Dr. Raglan's patients (Samantha Eggar) springs two evil mutant children from her body to act out her violent subconscious impulses. Mr. Skin brooded for hours on how to capture the nearly imperceptible boob slippage that occurs when Samantha gesticulates while wearing a flimsy robe. Thank God for slow motion!