Amen (1986)

Season 2: Episode 12

After the Deacon runs out of the church in mortal terror, the Reverend discovers that his panic was due to a fake rubber snake someone had left behind. And because of that incident, the Deacon has been the object of ridicule with the congregation. So, to help conquer his fear of snakes, the Deacon visits a therapist, who begins treating him for his phobia. Part of the treatment includes him staying in a room alone with a large boa constrictor.