1. Galactus
The devour of worlds is an all-powerful being. Galactus is known as the sole survivor from the universe prior to the big bang. Galactus is a being that feeds off of WORLDS. He harnesses the energy from the planets he devours. In the past Galactus could go centuries without feeding himself but his hunger grew, as did his destruction. He then set his eyes on Earth. As he attempted to destroy Earth, he was slowed down by his herald The Silver Surfer and then Reed Richards of The Fantastic 4 threatened Galactus with a weapon called the ultimate nullifier, a weapon in which would destroy the universe and Galactus in the process. Galactus was forced to spare Earth in exchange for the weapon but eventually he would go back on his word. At this point, Galactus was a shell of his former self as he had gone so long without 'feeding' that he was close to death. In a desperate attempt to devour Earth, Galactus was stopped by Earth's mightiest heroes. Succumbing to his own hunger, Galactus fell. He was on the verge of dying until Reed Richards came to his rescue. Why? The ultimate weakness, moral compass. Since then, Galactus vowed to never attempt to destroy Earth again as he now continues to grow stronger destroying other planets. Thanks a lot Dr. Richards.. Eventually Galactus was stopped by The Silver Surfer. This time for good. However being an energy source, you can't really say for sure. Time will tell when Galactus will make his triumphant return. Maybe one day it'll be on the big screen. At least I hope.
His Weakness? He grows weary when he goes too long without feeding off of worlds. Other than that, he's indestructible. The man eats worlds for lunch, what do you want me to say?
Now understand, Im no expert, Im just pretending to be so if you disagree with anything or anyone on the list feel free to let me know. I can take it. Be heard.