Dean Thomas

Dean Thomas is a Gryffindor student in Harry's year who is described as "a Black boy even taller than Ron". He is best friends with Seamus Finnigan and a football fan, which leads to his confusion about the complexities of Quidditch. Dean's mother is a Muggle and his father was a wizard who kept his blood status a secret and abandoned his family when Dean was very young as a measure of protection for his family against the Death Eaters, and was slain when he refused to join them. Dean was subsequently raised by his mother and stepfather, and has several half-brothers and sisters.[21]
Dean joins the D.A. in his fifth year, and also believes Harry and Dumbledore when they insist that Voldemort has returned, but when Harry and Seamus engage in a heated row over the Daily Prophet's allegations that Harry had merely fabricated the story, Dean refuses to take sides. At the end of the term, he begins dating Ginny, and temporarily fills in for Katie Bell on the Gryffindor Quidditch team in Half-Blood Prince after she is hospitalised. The relationship eventually ends after Ginny becomes annoyed with Dean when he tries to help her through The Fat Lady's portrait hole. Harry, though jealous of the relationship from the start, is accidentally responsible for the split: under the Invisibility Cloak and the influence of Felix Felicis, he accidentally brushes Ginny as she and Dean pass through the portrait hole. Ginny thinks that Dean is being pushy and overprotective, which leads to the fight that ends their relationship.
Dean's role is expanded in Deathly Hallows. Unable to prove that he is actually a half-blood, he does not return to Hogwarts and goes on the run from the Ministry, who are rounding up Muggle-borns upon Voldemort's orders. Harry, Ron, and Hermione first come across him during their mission as they eavesdrop on his conversation with fellow runaways Ted Tonks, Dirk Cresswell, and the goblins Griphook and Gornuk. Snatchers soon viciously attack the group; Dean and Griphook are the lone survivors but are captured along with Harry, Ron, and Hermione and taken to Malfoy Manor. They are all rescued by Dobby, who transports them to Bill and Fleur's Shell Cottage for protection. Dean returns to Hogwarts towards the end of the book and fights in the Battle of Hogwarts, in which he uses a Stunning Spell on an unnamed Death Eater, and when Dolohov attempts to retaliate against Dean, Parvati attacks Dolohov with a Body-Bind Curse.
Alfred Enoch has played Dean in all of the Harry Potter movies to date, and voiced the character in the Order of the Phoenix video game.