Gimli

Gimli is one of the main characters of The Lord of the Rings film series. He is the only dwarf in the Fellowship of the Ring, who has sworn his ax's service in Frodo's.  Though he has an enmity with Legolas at the beginning of the series, they gradually become best friends.

Personality
Gimli is competitive when it comes to entering "friendly competitons" with Legolas. He often tries to outdo his best friend, even making sure that he kills more Orcs than Legolas does.

When Gimli promised his ax to protect Frodo, he was swearing his loyalty to Frodo as well.

The Lord of the Rings (film series)
In the film series, Gimli is portrayed by John Rhys-Davies.

The Fellowship of the Ring
Gimli and his father Glóin have arrived in Rivendell to decide what to do with the One Ring.

Elrond summarizes that the Ring must be destroyed. Gimli rashly tries to do so with his ax, which proves ineffective, when Elrond says that the Ring can only be destroyed in Mount Doom, and therefore has to be taken into Mordor itself. Boromir calls this folly, and an argument bursts out. During the argument, Gimli joined in when he refused to trust an Elf with the Ring. Frodo announces that he will take the Ring to Mordor, which takes the others by surprise. After Gandalf, Aragorn and Legolas offer their services, Gimli joins to protect Frodo with his ax. He glares at Legolas, but both are willing to try to tolerate each other. Boromir, Samwise, Merry and Pippin join the group, and form the Fellowship of the Ring is formed.

They set out around December 25th and make their way to Mordor to the destroy the Ring. During one of their camps, Gimli suggests to Gandalf that they go through the mines of Moria but Gandalf disagrees because he will only use it if there are no other options. Sam spots a flock of birds heading their way and Legolas is able to identify them as Gandalf realizes that the south is being watched and, for the safety of the company, has them go through paths of Caradhras in the Misty Mountains. After they are nearly killed by Saruman, Gimli suggests the mines as he suggested to Gandalf. Frodo decides they go through the mines, to Gandalf's horror but respectfully acknowledges Frodo's decision. The company spends hours outside of Moria, because Gandalf cannot think of a way to get into the Mountains. Frodo was able to get the door opened, but as they entered, they saw that all of Balin's warriors were slain by Orcs, to Gimli's horror. hey are attacked by the Watcher of the Waters, which grabs hold of Frodo. Legolas manages to blind it with one of his arrows as Aragorn yells for them to make it to the cave. The Watcher uses one of his tentacles and manages to block the company into the cave, which forces them to take the route through Moria.

Though Gandalf cannot remember the way, he eventually figures out which hall to go through. When they discover Balin's tomb, Gimli cried over the loss of his cousin. Pippin accidentally alerts the Orcs and Balrog of their presence. A skirmish breaks out in the battle, with Gimli promises to fight to his last breath. A troll appears in the battle, knocking Gimli off as it impales Frodo. The company think Frodo is dead, but it is revealed he is wearing the Mithril shirt Thorin gave Bilbo, with Gimli telling Frodo that he is full of surprises.

Before they can catch their breaths, the company is forced to flee to the bridge of Khazad-Dûm when suddenly the Balrog approached them. Gimli refused to be tossed and threw himself instead. He nearly falls but Legolas catches Gimli by the beard and pulls him up to safety. After the entire company is brought to the other side, they run to safety but only because Gandalf stayed behind and fell in Moria. As they entered Lothlórien, Gimli "warned" Frodo, Sam, Merry and Pippin to stay close because the supposed elf witch that lives in the forest when they are cornered by Elves. The leader, Haldir showed disdain for the way Gimli spoke of Galadriel. After tough negotiations, Haldir allows the company.

When Gimli sees Galadriel, he is immediately taken in with her.

Before they depart Lothlórien the next morning, Galadriel asks Gimli what he wants from her. Instead, he asks for a strand of her golden hair. Legolas inquires what the lady gave him. Gimli told the elf about the strand of hair and was given three instead.

In the final act of the film, Gimli participates in the battle of Amon Hen, where Boromir was grievously wounded. Gimli and Legolas appeared as soon as Boromir passed away and held a small funeral in their fallen comrade's honor. The three companions realize that they cannot follow Frodo and Sam anymore because it is their quest now and instead that they go hunt Orc and Uruks to rescue Merry and Pippin. Gimli looks to Legolas and laughs before joining Aragorn as their quest to find their friends begins.

The Desolation of Smaug
Gimli appears in a portrait (along with his mother) that his father carried on the way to Moria. When Legolas took the locket from Glóin, Legolas asked who that was and implied the woman to be Glóin's brother. The dwarf gets angry that the elf insults his wife and mistakes her for Óin. Then, Legolas comes across a photo of a young dwarf, and asks Glóin who that is supposed to be, calling him a goblin mutant. Glóin responds that boy is his son, Gimli, with Legolas giving him a skeptical look.