One of my favorite things about the "Harry Potter" series -- and one of the things that makes it such a huge literary accomplishment -- is the way author J.K. Rowling made every little detail important. We might not have realized it back in the "Sorcerer's Stone" days, but she was already setting us up for some of the biggest reveals in the "Potter" saga. Did I mention that Harry has his mother's eyes?
During the course of the seven books, audiences were introduced to a wide array of colorful characters that seemed only moderately significant at the time. Little did we know that they would actually end up becoming the series' most important characters. Here's a look back at 10 "Harry Potter" characters who ended up being a lot more significant than we could have ever expected. Be warned -- many "Deathly Hallows" SPOILERS lie ahead!
10. Regulus Black
Who He Is: Sirius Black's brother, deceased Death Eater
Why He Didn't Seem Important: Sirius Black has been an important part of the series since the beginning (remember, that was Sirius's motorcycle Hagrid rode to drop off Harry at 4 Privet Drive), but his family was only described as being pure evil. Why did we care that his brother was a Death Eater?
Why He Is Important: Because he was a Death Eater who spurned Voldemort and stole one of his Horcruxes. R.A.B. wasn't alive by the time Harry got around to discovering his importance, but if he were Harry surely would have been thanking him a whole hell of a lot.
9. Bathilda Bagshot
Who She Is: Author of "A History of Magic"
Why She Didn't Seem Important: Let's face it, we never thought "A History of Magic" would be important for anything other than Hermione proving she was a better student than everyone else.
Why She Is Important: Little did we know that Bathilda and Albus Dumbledore were pretty good friends. Rita Skeeter magicked a lot information about Dumbledore from an old and wizened Bathilda, and... well, she serves a much more depressing purpose later on in "Deathly Hallows" as well.
8. Aberforth Dumbledore
Who He Is: The owner of the Hog's Head Pub
Why He Didn't Seem Important: Back in "Prisoner of Azkaban" days, Hogsmeade was a place of magical wonder and excitement with shops like Honeydukes and The Three Broomsticks. So it never seemed like the man who ran the Hog's Head Pub would ever end up being significant at all.
Why He Is Important: But when you're the only living blood relation to Albus Dumbledore, your level of importance rises significantly. Sure, there's that whole deal with the goat, but Aberforth is the only person able to tell Harry the truth about the life and lies of his mentor.
Who He Is: Gringott's employee
Why He Didn't Seem Important: Harry met him during his first trip to Gringott's in "Sorcerer's Stone," and we never heard from him again.
Why He Is Important: Not only is Griphook part of the resistance unit Harry, Ron and Hermione encounter when they're on the run, but he also is integral when it comes to stealing Hufflepuff's cup from Gringott's. He might not be the nicest goblin, but he does help Harry a great deal in his quest to destroy Voldemort's Horcruxes.
6. Gellert Grindlewald
Who He Is: Dark wizard Dumbledore defeated in an epic battle
Why He Didn't Seem Important: Other than a throw-away mention of Dumbledore's defeat of Gellert Grindlewald being one of the more spectacular wizard battles in the past century, Gellert didn't really make it into the books very often.
Why He Is Important: Turns out Gellert and Albus were BFFs back in the day -- and maybe more than that -- and Gellert was actually involved in some of the most defining moments of Dumbledore's life. And he really wanted those Deathly Hallows.
5. Mr. Ollivander
Who He Is: Wand shop owner
Why He Didn't Seem Important: Sure, he gave both Harry and Voldemort sister wands, but beyond being the man who sold wands to incoming Hogwarts students, Olivander never seemed particularly significant.
Why He Is Important: Well, Voldemort begs to differ, and tortures Ollivander during "Deathly Hallows" to try to get information about why his wand keeps reacting badly when it matches forces with Harry's. Ollivander also has some other big secrets up his sleeve, but we'll let you find those out in the films.
Who He Is: Former Malfoy family house elf
Why He Didn't Seem Important: Dobby served a big purpose in "Chamber of Secrets," but even with his quick appearances in the later novels he never seemed like he would get a major plot line again.
Why He Is Important: It wasn't until "Deathly Hallows" that he served Harry Potter for the last and most important time... and made us weep buckets.
3. Ginny Weasley
Who She Is: Ron's younger sister and fellow Gryffindor student
Why She Didn't Seem Important: When Harry first met Ginny in "Sorcerer's Stone," she was just the little sister of Ron Weasley who wasn't old enough to go Hogwarts. When she finally was old enough in "Chamber of Secrets," we only knew she had a huge crush on Harry and accidentally brought about the opening of the titular Champer. But it never really seemed like her importance would rival the Big Three's.
Why She Is Important: She is Harry's love and future wife, first and foremost, but Ginny also became a big part of both Quidditch and Harry's quest. Plus, she's the motivation behind the best quote of the whole series: Mrs. Weasley yelling, "Not my daughter, you bitch!"
2. Neville Longbottom
Who He Is: Harry Potter's fellow Gryffindor student at Hogwarts
Why He Didn't Seem Important: Neville was the goofy friend of Harry's who always seemed to screw up. He was great for a little comic relief, but not much else.
Why He Is Important: If only both we and Harry had known that Neville also matched Professor Trelawney's prophecy about the wizard who would bring down Voldemort. It was only because Voldemort chose to try to kill Harry that made their fates forever entwined. That earned Neville plenty of cred in our book. But when he also stepped up to lead Dumbledore's Army in resistance efforts at Hogwarts while Harry was on the run, we knew he was one of the saga's true heroes.
1. Severus Snape
Who He Is: Potions professor and Head of Slytherin House at Hogwarts
Why He Didn't Seem Important: Snape always seemed important, but only as the professor determined to make Harry's life a living hell.
Why He Is Important: Is he good or is he evil? We don't want to ruin the end of "Deathly Hallows: Part 2" for you, but let's just say the answer's a bit more complicated than that. And it's the contradictions of Snape's character that not only make him one of the most important people in the series, but by far the most complex and interesting.
Remember to keep coming back to MTV Movies Blog between now and the November 19 release of "Harry Potter and the Deathly Hallows: Part 1": As part of our Harry Potter Week, we'll be doling out a daily helping of "Potter" video, photos, features, polls and more -- including LIVESTREAMING our red-carpet coverage of the "Deathly Hallows" NYC premiere on Monday at 6 p.m. (ET)!
Who was the character in "Harry Potter" that most surprised you as being important?