Oscar Barrett (played by William T. Deutschendorf and Hank J. Deutschendorf II) is is a character in the film Ghostbusters II.
Oscar is Dana Barrett's baby boy, born 8 months prior to the beginning of Ghostbusters II. He is nearly sacrificed to serve as a new earthly incarnation of Vigo the Carpathian, but is saved by the Ghostbusters.
There has been speculation as to who Oscar's father actually is. Sigourney Weaver – on the June 14, 1989 episode of "The Arsenio Hall Show" – recalled she thought the father was the Violinist from the Lincoln Center scene. Referred to by Venkman as "The Stiff," the Violinist is given the name "Andre Wallance" in the novelization of the 1984 movie, 'Ghostbusters: The Supernatural Spectacular.' On the 1999 Ghostbusters DVD commentary track, both Joe Medjuck and Ivan Reitman state that Oscar's father is the Violinist. However, in July 2016, Ivan Reitman changed his opinion to Oscar's father probably being Peter Venkman (Bill Murray).
Peter says to Oscar in their first scene together, "You know, I... I should have been your father. I mean, I could have been..."