Treebeard
"It's talking, Merry. The tree is talking!
Pippin
As Merry and Pippin hurry deeper and deeper into the Forest they run into a huge tree-like being. He introduces himself as Treebeard, an Ent. These Ent's have been in Middle-earth for many Ages and are guardians of the Forests of Middle-earth, although, as Treebeard tells the hobbits, there are very few of them left now.
Treebeard is the oldest and Wisest of the Ents and was once a good friend of Saruman the White. The old Ent finds the hobbits suspects them of being Orc spies. All of the creatures in Middle-earth have been put into long lists made long ago, however hobbits have been left out of these rhymes and so Treebeard is not sure if they are who they say they are. He decides to take them to the White Wizard for information on the strange, short little creatures.
Of course Merry and Pippin assume that the White Wizard is Saruman, the very person the Uruk-hai were planning to take them too. But when they meet with the old man in white they learn that it is not Saruman as they suspected, but Gandalf, reborn and now made the leader of his order.
This satisfies Treebeard and the hobbits and they begin a journey to decide what is to be done about Saruman in Orthanc who has been destroying Fangorn Forest. Treebeard takes the hobbits to his home beneath a canopy of tall trees where the hobbits drink the Ent draught, a drink made from the water of the Entwash. This odd drink makes them a little, adding several inches to their current heights. Following a brief stop at Treebeard's home the Ent takes them to what he calls an Entmoot. A gathering of Ents where they plan to decide what to do about Saruman.
The Entmoot goes on for a great deal of time, as Ents are very slow creatures, in fact it days almost a day to introduce the hobbits to the gathered Ents. Finally the Ents decide that they will not become involved in the War, much to the disgust of Merry and Pippin, Treebeard promises to take them to the borders of their home-land and prepares to take them back. However Pippin suggests that Treebeard carries them back past Isengard, the very place that they don't want to go to, Treebeard cannot understand why they would want to go home this way, but as Ents think very slowly and hobbit's are very hasty in comparison he assumes that they must be right.
As they leave the forest Treebeard finds himself in a desolate wasteland that was once a forest full of life and beautiful trees. He sees the smoke rising from Isengard and something stirs inside of him. He lets out a deep booming voice and calls the Ents to war and so they begin their march down towards Isengard, to meet Saruman and get revenge.