Unidentified nearby wizard

This individual was an American Wizard who was among the patrons at the Blind Pig while Newton Scamander, Porpentina Goldstein, Queenie Goldstein, and Jacob Kowalski were negotiating with Gnarlak for information on the location of one of the missing creatures in 1926.

Behind the scenes
The Australian Wizard was portrayed by Sean Cronin in Fantastic Beasts and Where to Find Them.