A villain published by Marvel Comics. Ego, the Living Planet first appeared in Thor #132 in 1966.

Millions of years ago, in an area of the universe known as the Black Galaxy, a planet was formed which achieved consciousness. This planet calling itself Ego spent many years adapting and evolving. On a number of occasions, the explorer race known as the Rigelleans discovered Ego, only to have their ships destroyed by this unique being. Ego likes his privacy. Ego appeared like any normal planet with the exception that it appeared to have a huge face on one side of it and talked to people.

Eventually Ego decided to spread its influence across the stars and began to send parts of itself in the form of humanoid figures of great strength and power to other planets to take said planets over. This action brought Ego into conflict with the Asgardian god Thor who was traveling with a Rigellean Recorder. Ego and Thor clashed and Thor used his ability to control storms to caused immensely powerful storms within Ego's atmosphere. Ego, seeing his defeat at hand, recalled his invading forces and limped off with his peninsula between his legs.

Years later, the planet-eater Galactus came to Ego, intent on devouring the planet. Ego called upon Thor for aid and Thor used his powers, along with those of his father Odin to turn back Galactus. Ego was thankful for Thor's aid and agreed to let a group of refugees from planets that Galactus had destroyed settle upon him. Thor left with these self-proclaimed Wanderers setting up shop on Ego. Once Thor was away, however, Ego consumed the Wanderers.

Still later, a Rigellian scientist successfully removed a small portion of Ego and transported it back to Rigel. Once there, the scientist hoped to use this bit of Ego to help transform inhospitable worlds into habitable world. While in most cases amending the soil in your garden can help in making things more fertile, most of the time the peat moss or manure that you are using doesn’t get the occasional mad on and eat the people living on it. The Rigellian forgot this vital piece of information and soon the sample had become its own being calling itself Ego-Prime. It departed Rigel and eventually landed on Earth where it was challenged by Thor. During the ensuing fight, Ego-Prime released a particular kind of radiation that was a useful plot device to transform three normal humans into the New Gods. Thor was eventually able to defeat Ego-Prime.

Meanwhile, the loss of a piece of it had driven Ego out of its continental sized mind. Ego wreaked havoc on the planets in its area and it took the combined might of Thor, Hercules, Firelord, and Galactus to bring the insane planet into check. Galactus secured a huge engine to the southern pole of Ego, which was programmed to move it out of orbit and fly it on a course through the universe that would keep it away from inhabited space.

The enemies of Ego only succeeded in giving the Living Planet a means of mobility. Up to that point, Ego could only do so much harm, because they know right where he was going to be: orbiting a sun in the Black Galaxy. After this adventure, Ego seized control of the engine and used it to putter around the universe, causing death and destruction where he wanted. His first stop was Earth in an attempt to get revenge upon Galactus, fuzzy logic at best.

The approach of Ego, the Living Planet caused natural disasters galore, but the destruction was reversed by an immensely powerful human named “Skip” Collins, who used his vast mental powers to undo the global damage and make everyone forget about it. Hey, this was during a John Byrne writing stint on the Fantastic Four. Stuff like this happened all the time. Meanwhile, the Fantastic Four traveled to Ego and Reed Richards was able to disable half of the rocket engines, causing Ego to travel towards Earth’s sun and be torn apart by the gravity.

Ego, the Living Planet was able to reform itself using its vast powers, but the result left it spent and wasted. It resorted to eating other life forms for energy and some of its first victims were a group of Dire Wraiths and two Space Knights from Galador. The disappearance of the two Space Knights brought the greatest Space Knight, Rom to Ego. Rom defeated Ego, rescued his fellow Space Knights and banished the Dire Wraiths to Limbo, the Marvel Universe version of the Phantom Zone.

Later, Ego sided with the Elders of the Universe against Galactus and clashed with Mantis and Galactus’s former herald, the Silver Surfer. He also fought against the hero Beta Ray Bill when he threatened the other members of Bill’s race. Of late, he has tried to rid other planets of the humanoid life living on them during the Maximum Security series.