Main characters
Vivien Endicott-Douglas as Marnie McBride, the main protagonist. An 11-year old girl who moves from Denver to Edinburgh following her mother's death, Marnie discovers she has magical powers and is the Chosen One, destined to find the Book of Forbidden Knowledge. At first moody and reluctant to take on her role, Marnie embraces her destiny, coming to terms with her mother's death. Shoebox Zoo was Endicott-Douglas' first acting role in television.
Jason Connery as Ross McBride, Marnie's widowed father who works as a librarian at the University of Edinburgh.
Connery also cameos Angus McBride, Marnie's ancestor, who marries Stone Bear's daughter in 1811.
Peter Mullan as Michael Scot, an eleven-hundred year oldalchemist, and Wolfgang's estranged father. Based on the historical figure, Michael created both the Book and Toledo in his pursuit for power, corrupted by his own dark intents, leading to many of the events that set up the series' backstory. Although cantankerous, he is wise and mentors Marnie in both magical and personal issues, coming to acknowledge his own sins in the process.
David McKay as William McTaggart, Michael Scot's loyal manservant, cursed with immortality for his part in the Book's theft and loss.
Tony Donaldson as Professor Juan Montoya de Toledo, the series' antagonist. A shapeshifting homunculus created by Scot, Toledo seeks to acquire the Book to conquer the world and prove his superiority to his creator. He is suave and manipulative, but short-tempered and sociopathic. Due to his shapeshifting abilities, Toledo takes on the form of several disguises, including:
Maxi Moffat as John Roberts, Marnie's classmate.
Kirsty Elkin as Dr. Joanna Robertson, a psychiatrist.
Yudii Mercredi as Kyle Stone, Marnie's friend of Lakota descent. Kyle is a descendant of Chief Stone Bear, possessing his own powers called "horse magic", destined to succeed his grandfather Nathaniel as the local medicine man.
Gordon Tootoosis as Nathaniel Stone, Kyle's grandfather and a medicine man.
Natascha Girgis as Aurora Dexter, an antagonist in the second season. A television medium from Valentine, Nebraska, Aurora is destined to become the Dawn Queen, a malevolent entity who is prophesied to use the Book's dark magic to corrupt mankind. Toledo possesses her to ensure the prophecy comes to pass.
Rik Mayall as Edwin, the pompous, self-proclaimed leader of the Shoebox Zoo, transformed into a metal toy eagle. His name and inability to fly is a nod to Olympic ski jumper Eddie the Eagle.
Alan Cumming as Bruno, a kind-hearted though woolly-minded toy bear made of stone.
Siobhan Redmond as Ailsa, a cynical and distrusting golden toy adder.
Simon Callow as Wolfgang Scot, Michael's son, transformed into a wooden toy wolf, who carries a deep resentment towards his father.
Callows also voices Hunter, a free-spirited Native American spirit who materialises in a horse-shaped dancing stick. He repeatedly introduces himself as "Sunkwaki, Spirit of the Horse Dance, son of Wakangli, war horse of Chief Inkpaduta, loyal servant of Wakan Tanka, etc."
Bill Paterson as the Storyteller, the series' narrator. In the final episode, it is implied this unseen character inherits the Shoebox Zoo as their next master.
