Ent

The Ents are the main antagonist(ent-agonist) of Ent Adventures. They invaded Gake Academy and Zoto and the others have to fight against them. Ents are living trees that can move and attack.

Treebeard(or Fangorn) is the leader of the Ents and the protagonists have not yet fought him, but in episode 362 he said that sometime soon the protagonists will have to fight him.

They can turn people into za.

If they are destroyed, they turn back into the tree they were aasquerading as. Each species of Ent correstponds to a species of tree. The first Ent that was destroyed in episode 3 was described as an Ent that came from an oak tree. They had to cut down the tree to get it out of the school.