Frank Dillane cast in 'The Walking Dead' spin-off

Los Angeles: 'Harry Potter' actor Frank Dillane has been cast in the 'Walking Dead' spin-off pilot.

AMC officially ordered the pilot - a sister series to its hit zombie drama - back in September. Dillane will play a young man with a history of drug addiction, Deadline reported.

The 23-year-old British actor is best known for playing young Tom Riddle in 2009's 'Harry Potter and the Half-Blood Prince'. 'Into the Storm' star Alycia Debnam Carey has also joined the pilot, playing the ambitious sister of Dillane's character.

Adam Davidson will direct the project, expected to shed light on an unseen part of the zombie apocalypse.