2) #188 (May 1985) in a story titled "Mogo Doesn't Socialize" and was created by writer Alan Moore and artist Dave Gibbons.

Although initially a one-off character from a short story, the planet has grown in importance in the Green Lantern mythos and is a necessary part of the process for distributing power rings as well as a destination for Corps members to recuperate.

When Parallax, who was at that time inhabiting the body of Hal Jordan, destroyed the power battery on Oa and slew the Guardians, Mogo lost contact with the Green Lantern energy that helped sustain him.

Having relied on the energy of the power battery to sustain him, Mogo lost consciousness and drifted through Sector 1014 until he was discovered by a nomadic alien race.

Mogo later revealed to Rayner that he was relieved the aliens had left, and that he had planned to give them terrible weather in retaliation for their pollution.

[5] Mogo played a major role in the conclusion of Infinite Crisis, in which the Green Lantern Corps, Superman and Kal-L stop the villainous Superboy-Prime.

2) #11, Mogo apparently shows Kilowog images of his dead species, pushing him into madness and hatred toward the Green Lantern Corps.

This behavior seems to be caused by the virus Despotellis of the Sinestro Corps and, according to Guy Gardner, was actually unnoticed by the planet, who was immune to the fungus himself (stated by Green Man in issue #13).

The Sinestro Corps attack Mogo with Ranx, who started to drill into the planet, with the intention of planting the blink bomb.

It was revealed that Mogo is the one who guides the rings of deceased Lanterns to find new replacements and that if he should die, the Corps would be unable to recruit members in this manner.

[10] During the attack, Salaak decrees that all rings from fallen Green Lanterns should be sent to Mogo, so as not to endanger the lives of potential rookies.

[11] Soranik Natu then sends all injured patients from the fight to Mogo, but is sidetracked by Kyle Rayner being attacked by a Black Lantern Jade.

While Miri, a Star Sapphire, attempts to revert Guy to normal, it is ultimately Mogo who manages to purge the infection of the red light.

[16] Krona then used Mogo to send out hundreds of Green Lantern rings across the universe to recruit more members to be brainwashed.

[18] After the ensuing chaos, along with Krona's death and Sinestro gaining a green ring, Kilowog states that as long as Mogo's corpse floats above Oa, the Corps will be disheartened.

The resulting reaction from Mogo's body being put into the sun causes a Mogo-like Green Lantern stripe to appear, forever honoring the planet.

They are held prisoner by a space pirate using Mogo's power as the ship's energy beam weapon to attack the planet's core, threatening their lives.

Mogo freezes the doppelgangers and confesses the ruse to the Corps, stating that it was done to test their will and strength and prepare them to fight against the First Lantern.

[28] In the Legion of 3 Worlds, it is revealed that in the 31st century Mogo has been long dead and without him, there was no way to distribute the rings and thus no Green Lantern Corps.

[32] Following Henshaw's defeat, Ganthet reveals the Guardians are secretly rebuilding Oa and intend to return the Green Lanterns' main base of operations there to allow for Mogo to recover.

[34] An alternate universe variant of Mogo who is home to a Xenomorph colony appears in Green Lantern Versus Aliens.