Another Hogwarts alumni (kinda), Frank Dillane came to most people's attention when he portrayed a young Tom Riddle with all the requisite creepiness in Harry Potter and the Half-Blood Prince and since then has had prominent roles in In the Heart of the Sea, Sense8, and most recently Fear the Walking Dead. The son of Game of Thrones actor Stephen Dillane, this is one apple that doesn't fall far from the tree.