Who is Merry in the movie?
Merry Brandybuck is a friend of Pippin Took and Frodo Baggins. He lives in Buckland, and has a quick head. Slightly more mature than his companion, he and Pippin pull a lot of pranks but always stick together.

Who was Merry in the book?
Meriadoc Brandybuck is a good friend of Frodo Baggins, Fredegar Bolger and Peregrin Took. He is a smart Hobbit of some social status, and lives in Buckland. He insists on travelling with Frodo, first to Crickhollow, later to Rivendell and in the end even to Mount Doom – though he never gets there…

Changes in Fellowship of the Ring
Introductions
Merry and Pippin are introduced to the movie audience at Bilbo’s birthday party, mocking around with Gandalf’s fireworks and creating quite a chaos.
In the book, they are introduced separately: Merry, who Tolkien refers to as a good friend, helps Frodo distribute the presents Bilbo left for everyone (1.I.. He then ventures out to search a house for Frodo in Crickhollow after it becomes clear that Frodo has to leave the Shire, and takes part in ‘the conspiracy’ (I.V.).

General Character Changes
Meriadoc Brandybuck is a witty but thoughtful hobbit, with an almost aristocratic air about him. He certainly isn’t the prankster the movie makes him out to be, though he is often light-hearted and a bit mischievous. Although (Pippin is the one who suffers the most under the weight of ‘comic relief’ (or should I say the unbearable lightness?), Merry too is greatly reduced as a character.

In ‘Fellowship of the Ring’, Merry is a background character with little weight on the story, but he already has his own personality traits: it’s most characteristic that he would be the one who goes out for a walk at night in Bree and encounters a Ringwraith (1.IX), or that he would be in charge of the logistic side of both the move to Crickhollow and the journey to Rivendell. It’s also Merry who helps solve the riddle on the doors of Moria.

Indescernable Background Hobbits
A lot of viewers have a problem keeping Merry and Pippin apart. In the book, their characters were more different, and they weren’t always teamed up. This is one of the side effects of the enlargement of Sam‘s part in the movies, and the reduction of mainly Pippin but also Merry to comic relief.

Some simple tricks to keep them apart:
– Merry’s the smart one. This is actually true to the book: Merry is a serious young hobbit, who makes an almost aristocratic impression. He’s more thoughtful and moderate than Pippin, but he’s also a little older so that may have something to do with it.
– Pippin’s the one with the Scottish accent. That helps a lot in keeping the two hobbits apart, but on the downside it gives Pippin an extra touch of funniness. Merry’s the one with the quite indiscernible accent, at least for a not-native speaker. So if anyone knows what accent he has, the Viewpoint submission form is the place to be!
– Merry’s the one with the yellow vest and the bigger nose.