Colin Farrell is the latest big name casting addition to the upcoming Fantastic Beasts and Where to Find Them.
The True Detective star will play a wizard who encounters Newt Scamander during his journey to study magical creatures in America.
The Harry Potter spin-off will also star Ezra Miller, Alison Sudol, Katherine Waterston and Eddie Redmayne as the magizoologist and textbook author Newt.
David Yates, who directed the last four Harry Potter films, will take the reins on Fantastic Beasts And Where To Find Them, which is set decades before Harry Potter's story.
He said: "Eddie is a fearless actor, brimming with invention, wit and humanity. I couldn't be more excited about the prospect of working with him as we start this new adventure in JK Rowling's wonderful world, and I know she feels the same way."
Rowling will make her screenwriting debut on the film, which will be co-produced by her fellow Harry Potter collaborator David Heyman.
However, fans will have to wait a while to see the flick as Fantastic Beasts is slated for a December 2016 release.