Freddie Had a Little Lamb - S3.E17

Fred puts a glass door on the andromeda chamber. The glass isn't thick enough, so the effect of an experiment went through and into Fred. This experiment changes him into a crazy doctor. The rest of the episode is a parody of ""The Silence of the Lambs"", with Fred playing the part of Hannibal Lector and Tina playing the part of the woman who helps him. Tina eventually figures out a way to reverse the effects, and Fred comes back to his normal self.