Tree-men

Tree-men are a kind of giant or a descripion for giants.

Background
Hob speaks of seeing a Tree-man or giant up by the High Moor. Though it us unclear if he saw a giant, an ent or even a huorn. But most folks in the shire assume these wre rumors of giants.

Earlier legends
Voronwë and Eärendel set sail in Wingilot and are driven south into dark regions with fire mountains. They encountered; tree-men, Sun-dwellers, [pygmies and the Sarqindi.

Behind the scenes
In an early draft of LOTR Frodo would have been captured by the Giant Treebeard. Treebeard was revised into a good character.