Forest King

The Forest King (森林王, Shinrin-ō) was a Mysterious Being who ruled over the Forest Tribe and wanted to return the lost greenery to Earth at the cost of the humans inhabiting it. He was killed by Genos.

Appearance
The Forest King is a large and monstrous-looking tree creature, standing several stories high and has what appears to be another face in his abdomen and several thick branches covering his body that act as his limbs. His own face sports five pitch-black eyes and a mouth full of hole-like openings.

Personality
The Forest King sees humans as nothing more than mere fertilizer that his kind needs in order to carry on his scheme of returning the lost greenery to Earth.

Fall of the Hero Association Arc
After four heroes of the Association fought and harmed his followers, the Forest King himself confronted the heroes and easily defeated and captured them. As he was about to feed them as fertilizer to his kind, another hero appeared, annihilated his entire army, and then proceeded to defeat the Forest King himself.

Abilities and Powers
The Forest King could singlehandedly defeat four professional heroes of the Hero Association with little to no effort, with the heroes being impotent against him.

Physical Abilities
Immense Strength: The Forest King could use his branches to easily crush with great force anything in his grasp.

Immense Durability: The Forest King could endure the attacks of an A-Class Hero without any scratch.

Trivia

 * The Forest King is the ninth of many "Kings" mentioned in the series, the others being the Subterranean King, the Beast King, the Deep Sea King, the Ancient King (anime-only), the Underworld King (anime-only), the Sky King, the "second Sea King", and the Monster King.