Hexxus

This is Hexxus. 

He was an evil Spirit of Destruction in "Ferngully: The last Rainforest". 

For the first Time, Magi Lune defeated Hexxus by imprisoned him 

inside the enchanted Tree and saved Ferngully. 

I think Hexxus sang "Toxic Love". 

Once Zak turned off the Lever, 

Hexxus lose the Energy that he was gaining from it and disappeared. 

Hexxus became an evil giant Demonic Fire Breathing Skeleton Monster. 

That Skeleton Monster has sharp Teeth instead of grinding Teeth 

just like Human Skeletons have. 

I think Hexxus looked like the Demon Monster 

made of black Stuff from my favorite Music Video "Swan Meat".