I'm looking for texts and talks, where Zizek responds to the Mimetic Theory of Rene Girard. Also the other way around would be interesting.
I found some references to these commentaries in Monica Germana(ed.) e.a., Apocalyptic Discourse in Contemporary Culture: Post-Millennial Perspectives on the End of the World, p. 52, 2014.
Žižek indeed talks about mimicry in "Slavoj Žižek & Boris Gunjevic, God in Pain: Inversion of Acopaclypse, New York: Seven Stories Press, p. 124-126, 2012"; where in these passages, the mimicry seems related to the feminine.
In the same book (click here to download) on pages 63-64: René Girard and scapegoating are mentioned.
More assumed comments/allusions of Žižek on René Girard can be found in the source linked to above.
There is some discussion of Girard in this video (discussion with Jean-Pierre Dupuy) around minute 32.
Some Zizek excerpts commenting on Girard (actually, mostly just paraphrasing) can be found here: https://mimeticmargins.com/2017/11/28/slavoj-zizek-on-atheism-christianity/