Suggestions by @harrypotterfan7

Tom Hardy

as Fenrir Greyback in Harry Potter

Peter Capaldi

as Rufus Scrimgeour in Harry Potter

Stephen Fry

as Horace Slughorn in Harry Potter

Eva Green

as Bellatrix Lestrange in Harry Potter

Millie Bobby Brown

as Nymphadora Tonks in Harry Potter

Idris Elba

as Kingsley Shacklebolt in Harry Potter

Chiwetel Ejiofor

as Kingsley Shacklebolt in Harry Potter

Elizabeth Moss

as Dolores Jane Umbridge in Harry Potter

Rosamund Pike

as Rita Skeeter in Harry Potter

Martin Freeman

as Arthur Weasley in Harry Potter

Liza Tarbuck

as Pomona Sprout in Harry Potter

Peter Dinklage

as Filius Flitwick in Harry Potter

Tilda Swinton

as Professor Sybill Patricia Trelawney in Harry Potter

Mr. Bean

as Peeves in Harry Potter

Paul Dano

as Peter Pettigrew in Harry Potter

An Unknown Child Actor

as Fred Weasley in Harry Potter

An Unknown Child Actor

as Ron Weasley in Harry Potter

An Unknown Child Actor

as Neville Longbottom in Harry Potter

An Unknown Child Actor

as George Weasley in Harry Potter

An Unknown Child Actor

as Draco Malfoy in Harry Potter