Editing World of Warcraft (section)

====The Old Gods====
Giant Cthulhu space cancer sent by the Void Lords to consume planets and find and corrupt a Titan worldsoul. They corrupt everything they touch and that serves them. In older lore they acted on their own, but they go retconed into being creations of the Void Lords. Their primary purpose is to corrupt a titan world-soul and become unstoppable universe-eaters. Chained beneath Azeroth due to presumed indestructibility (and the very bad side effects if they are killed) by the Titans. They are breaking out one by one. The four Old Gods (on Azeroth) are:

* C'Thun - Imprisoned in a massive desert in the southwest of Azeroth, this Old God commands an army of insect creatures that infested the research station that was built around its body (it had arachnid minions, but they were separated during a war and became atheists before they all died; Northrend's Nerubians are descended from them). It consists of a fleshy body covered in eyes with a mouth on top and tentacles everywhere. Feigning death after a battle with a titan, it was able to heal enough to pose a threat yet again until it was killed once again.
* Yogg-Saron - Imprisoned in the far north of Azeroth, this Old God corrupted the leadership of the remaining titan minions on Azeroth before almost breaking out. It was only imprisoned because at that point the Titans learned killing Old Gods had very bad side effects for the world, so it was imprisoned and its power contained. Its body is covered in mouths, even where it looks like there should be eyes, and it also has a tentacle theme going. Its blood can be strip-mined and made into decently powerful things. This stuff, called Saronite, on the other hand is one of the most corruptive substances on the planet and only the Undead can actually use it safely, due to the Lich King overriding Yogg-Sarons whispers. Claims to have invented Death, and was implied to be fighting the Lich King for control of the Scourge (or subtly drove Arthas down his road when he was in Northrend, it's not really clear). Has minions called the faceless ones (think Illithid, but with no mouth).  Killed during Wrath, but Legion hints it's either making a comeback or manifesting something like the Sha.
* N'Zoth - Imprisoned somewhere under an ocean, this Old God corrupted the Emerald Dream into the Emerald Nightmare and commanded Deathwing to blow up Azeroth. Has different faceless one minions. Looks like a multi-eyed octopus with a crown of teeth around its head. Also invented Naga and worked with Azshara to escape his prison.  Raised the city-throne of <s>R'yleh</s> Nya'lotha (by summoning it to the past from a future where he had already built it) and started driving people around the world insane for a few hours, only to get promptly Kamehameha'd by the player.  
* Y'Shaarj - The former Old God king. Got one-shot by Aman'thul, the leader of the titans, leaving the Well of Eternity as a bleeding wound in the world. "Imprisoned" in the center of Pandaria, this Old God died in the war with the titans, leaving only its heart instead of a giant mass of flesh embedded into the planet. Had some bro-ish mantis minions. Its death caused negative emotions in Pandaria to turn into monsters that look like spiky tentacle monsters covered in oil. After the destruction of its heart, it went from dead-dead to dead-dead-dead.
* Something somewhere - There used to be a fifth Old God, but Blizzard seemed to have decided/realized they had no plans for it so they retconned it out of existence. It might have been Xal'atath, who was an Old God that got eaten except for a single claw that became a dagger her essence inhabits. May have originally intended to be Azeroth itself (check the name; Azeroth -> Azathoth).  Later retconned to be G'huun. 
** G'huun - After trying to make a substance that kills the Old Gods without harming their surroundings (see Y'Shaarj), the titans ended up accidentally making a fifth one, themed after rot, so they put the facility into lockdown to keep it contained there.  Imprisoned in the swamps to the north of the Zandalari Empire, a corpulent slug with stubby legs and a lamprey-like mouth. He teaches the secret of Blood Magic, and had corrupted several of the titan's creations.