Muggles' Guide to Harry Potter/Characters/Dean Thomas

Overview
Dean Thomas is a Gryffindor in Harry's year, who shares a dormitory with Harry, Ron Weasley, Neville Longbottom, and Seamus Finnigan. Although there is no particular description in the UK editions of the book, in the US edition it is mentioned that he is a black Londoner.

Philosopher's Stone
Dean is sorted into Gryffindor where he meets Harry Potter, Ron Weasley, Seamus Finnigan and Neville Longbottom.

Dean, apparently of Muggle origins, like Harry, has never heard of Quidditch, and so has a poster of the West Ham football team that he puts up over his bed in the dormitory. Ron, who had had an argument with Dean about football and how a game with only one ball and two goals could be any good, is seen at one point poking the poster with his wand to try and make the players move.

At Harry's first Quidditch match, Seamus, Neville, and Dean have made a banner that reads "Potter for President". Dean, who is apparently something of an artist, had painted the Gryffindor lion underneath that, and Hermione had charmed it so that the paint flashed different colours. When the Snitch first appears, Harry is about to grab it when he is fouled by Marcus Flint, the Slytherin team captain. Dean demands that the ref send Flint off, and Ron explains that you can't do that in Quidditch.

Later on in the year, when Harry, Neville and Hermione are caught wandering the corriders at night, Gryffindor house loses a total of 150 points, which puts them in last place. It is possible that Dean was one of the Gryffindors that was mad at Harry, Neville and Hermione for lowering their chances of getting the House Cup.

Towards the end of the year, Albus Dumbledore awards points to Harry, Ron, Hermione and Neville for their good actions that lead to stopping Quirinus Quirrell from stealing the Sorcerer's Stone. The points that he awards them puts them ahead of Slytherin House, making them win the House Cup for the first time in seven years. It can be assumed that Dean was very happy by this.

At the end of the year, Dean rode the Hogwarts Express to go back to his parents.

Chamber of Secrets
Dean joins Gilderoy Lockhart’s dueling club and witnessed Harry speaking parseltongue, a rare dark art. He also shared speculation about the Chamber of Secrets during the year. He was also believed to be at risk due to him being muggleborn.

Prisoner of Azkaban
Dean offers to forge Uncle Vernon's signature on Harry's permission slip to facilitate Harry's visiting Hogsmeade. Unfortunately, by this point Harry has already told Professor McGonagall of the issue with his permission slip, so this does not happen.

Order of the Phoenix
When Harry and Neville reach the dormitory on Harry's first night back at Hogwarts, Dean says that Seamus has had a rough summer, largely due to the scurrilous reports in the Daily Prophet which have been painting Harry as a dangerous lunatic and Dumbledore as a senile old fool. After Seamus and Ron reach an accommodation, Ron asks if anyone else had a problem with Harry. Dean says that it is not a problem for him, his parents are Muggles.

In the first Defence Against the Dark Arts class of the year, Hermione wonders when they will be actually practicing defensive magic. Professor Umbridge says that she can't see any time when people will be attacked in her classroom. Echoing Harry, who Umbridge is ignoring, Dean points out that if they are going to be attacked, it will be outside the classroom. Umbridge over-sweetly explains that the Ministry feels that understanding the principles of defensive magic will be sufficient.

Dean is one of the students who attends the first meeting of what becomes Dumbledore's Army, in the Hog's Head.

Harry gives an interview to Rita Skeeter about the events surrounding Voldemort's return. The following Monday at dinner, he apparently tells Dean and Neville about it. Dean is awestruck, and says he can't wait to see Umbridge's reaction.

Dean is present in the first class with Firenze, the centaur teacher brought in to replace Professor Trelawney after Umbridge sacks her. Firenze says that he would prefer to teach these classes in the Forbidden Forest, but this is not possible, as he has been banished by his herd. Dean, excited at the possibility that there are more Centaurs, asks if Hagrid had been breeding them, like the Thestrals, and apparently immediately realizes that he has said something horrible. Firenze, after a pause in which Dean evinces extreme embarrassment, says that Centaurs are a race apart, having little to do with humans.

Dean is pleased to hear that OWL results won't arrive until sometime in July, as that means he won't have to worry about them until the middle of vacation. We see him later, practicing Charms theory with Seamus Finnigan.

Following the final OWL exam, Dean and Seamus tell Harry that they are planning a dusk-to-dawn end-of-OWLs celebration and suggest that one of the students, Harold Dingle, believes that he can get some Firewhisky. Harry is in a panic, trying to get in contact with Sirius, and pushes past without answering.

It is noted that Hedwig and Pigwidgeon are disturbed by Ron's outburst when he learns that Ginny is going out with Dean.

Half-Blood Prince
He is going out with Ginny Weasley without her brother Ron's approval. What makes Ron even madder is when he catches them "snogging" (kissing) in a secret hallway. Their relationship is ended when Harry, under the effects of a good luck potion, bumps into Ginny while under his Invisibility Cloak. Ginny thinks Dean purposely pushed her so he could help her get inside. So, much to Harry's good fortune, they break up.

Deathly Hallows
It is only in this book that we learn that Dean actually has been raised only by his mother. As Dean cannot prove that his father was a wizard, he is an outlaw for daring to have a wand. When we first see him, he is on the run with Ted Tonks, one Dirk (probably Dirk Cresswell) and the goblins Gornuk and Griphook. Ted, Dirk Cresswell, and Gornuk are ultimately killed, but Dean and Griphook escape only to later be captured by Snatchers and taken to Malfoy Manor alongside Harry, Ron, and Hermione. Dobby arrives, and Harry has him carry Dean, along with Luna Lovegood and Ollivander who are also prisoners of the Malfoys, to safety. (Griphook is also saved, shortly after.)

Dean remains in safety at Shell Cottage, but rejoins our story to take part on the final battle at Hogwarts. As the gathered members of Dumbledore's Army and the Order of the Phoenix leave the Room of Requirement to assist in the defence of Hogwarts, Dean takes Luna Lovegood's hand, and they leave together.

Later, during the Battle of Hogwarts, the trio see Dean - now with a wand - duelling Antonin Dolohov, while Parvati Patil is nearby duelling Travers.

Strengths
Dean is shown to be a skilled artist. It is Dean who paints the Gryffindor lion on the "Potter for President" banner that appears at Harry's first outing on the Gryffindor Quidditch team, in Harry Potter and the Philosopher's Stone, and in Harry Potter and the Goblet of Fire he is apparently responsible for some other banners.

As he has also been a member of Dumbledore's Army, Dean is learned in defensive magic. During the final battle, he manages to win himself a wand, despite initially entering the mêlée without one.

Relationships with Other Characters
Dean was once in a short-lived romantic relationship with Ginny Weasley, although there are few details about this relationship and it is only mentioned in relation to Harry Potter's own love interests.

He is also best friends with Seamus Finnigan and gets on well with the other boys in his dormitory.