Exorcism
In Catholic Christianity, exorcisms are performed in the name of Jesus Christ. A distinction is made between a formal exorcism, which can only be conducted by a priest during a baptism or with the permission of a bishop, and "prayers of deliverance" which can be said by anyone.
The Catholic rite for a formal exorcism, called a "Major Exorcism", is given in Section 11 of the Rituale Romanum. The Ritual lists guidelines for conducting an exorcism, and for determining when a formal exorcism is required. Priests are instructed to carefully determine that the nature of the affliction is not actually a psychological or physical illness before proceeding.
Pazuzu (The Exorcist)
In "The Exorcist" television series, Pazuzu in its natural form is portrayed by Robert Emmet Lunney. Its victims are an older Regan, portrayed by Geena Davis, and Regan's daughter Casey, portrayed by Hannah Kasulka.