It’s funny that Hearthstone dedicated an expansion to the chittering minions of the Old Gods. These Cthulhu-inspired monstrosities are drawn from one of the darkest and most mysterious parts of World of Warcraft lore, and are responsible for some of the most memorable encounters ever designed in the game. But yeah, now they’re immortalized in a free-to-play card game that’s completely dwarfed the MMO source material in terms of cultural relevancy. World of Warcraft is currently struggling to stay above five million active subscribers , while Hearthstone hosts about 50 million accounts . It’s especially hilarious that C’Thun is handed out for free to anyone who logs in. The C’Thun starter deck? I never thought I’d see the day. If you know his history, you’d be laughing too.

This is C’Thun: a mountain of blubber and tentacles and splattered eyeballs, threatening doom, hatred, madness, and death to any adventurer dumb enough to enter his forlorn halls deep in the fabled city of Ahn’Qiraj. Legend spoke that he could kill powerful dragons with his gaze, and effortlessly gobble the souls of the mortals who confronted him. C’Thun ruled World of Warcraft in 2006, long before any expansions or modernizations or datamining. And back then no monster, no matter how fearsome, went unchallenged by enterprising players in lonely dorm rooms on Tuesday nights.

Back then you conquered the Prophet Skeram, bested Battleguard Sartura, kept your cool through Fankriss the Unyielding, resisted the poisons of Princess Huhuran, figured out the tricks of the Twin Emperors, and there you were: on the perch of destiny with a giant, luminescent eyeball. And you died. Horribly, again and again and again. The early days of World of Warcraft were often defined by difficult, demanding bosses stymying the gear flow and progression charts of even the best raid groups, but C’Thun was untouchable. Nobody came close.

Let’s go over his tactics. C’Thun came equipped with an eye beam capable of hitting a player for an as-ridiculous-as-it-seems five million damage if your positioning was bad (your average tank had about 9,000 HP fully buffed.) He spawned tentacles that could quickly wipe your raid if not handled cleanly and efficiently. Occasionally he’d dump players into his stomach, where they’d slowly succumb to digestive acid and be addled by nightmarish, fleshy claws. If you do everything right, you might make the god vulnerable to your pathetic attacks for a scant 45 seconds. After that his shields would go back up and you started the whole process all over again. You’d be lucky to drop him below 90 percent.

C’Thun devoured every guild that knocked on his door. All the clout, and savvy, and dedication swallowed up in the yawning maw of his madness. The same people who bested Ragnaros, Nefarian, Chromaggus, and every other malefic villain Azeroth had previously offered simply could not come up with an answer.

Come at the king and you best not miss. Actually, it didn't matter. He'd kill you anyway.

“We probably had like 20 attempts on our first night on C’Thun that didn't even make it through the first phase of small eyes,” says Sokur, who played a hunter in vanilla Warcraft and raided in a guild called Divine Heroes. “After every night of attempts at least five people would quit—either from frustration or whatever else. I remember one time we only had like 20ish people show up [out of 40 slots] for a C’Thun progress night.”

C’Thun was added to WoW on January 23, 2006. Guilds started making attempts on him in early February, and he was finally solved in late April—after a couple giant nerfs were handed down by Blizzard. To put that in perspective, Mythic Archimonde , the end boss of the last raid in Warlords of Draenor, was dropped in three weeks, which is considered a long time in 2016. When you slam your head against a hopeless fight for 80 days, you might start to get a little frustrated.

It seemed impossible. Actually, it was impossible.

“The fight was bugged,” says Failure, who was the leader of the top-ten raiding guild Risen when C’Thun reigned supreme. “These large tentacles would spawn under you and send you flying to the ceiling, and then you’d come back down and take lethal damage. If that happened once we could still manage, but once it happened a second or third time we’d be screwed. So naturally people started to think the fight was kind of dumb. It was just a random bug that would hit you.”

"Basically, every 60 seconds the encounter required your raid to do roughly 230,000 damage."

Bugs weren’t the only problem. C’Thun demanded an insane amount of focus and optimization. He stretched the limits of what a well-equipped, well-composed 40-man raid group could accomplish. Today, Ion Hazzikostas is a developer on World of Warcraft, but before that he was the guild leader of Elitist Jerks, and after crunching some numbers, famously concluded that C’Thun was mathematically impossible in his original state.

“Basically, every 60 seconds the encounter requires your raid to do roughly 230,000 damage in order to keep up with the various spawns,” he wrote in an ancient Warcraft forum post that’s been scrubbed from the internet. “Now, a 40-man raid can certainly accomplish that on a single target. But when some people are in C'Thun's stomach, and the targets of that DPS are spread throughout the room, and when clustering at all means that you get destroyed by a spawning tentacle or a jumping eye beam, the end result is simply impossible.”

It’s interesting to read the desperate, agonized laments of those players now. C’Thun was the very first boss to bring World of Warcraft’s raiding community to their breaking point. Some players looked for divine intervention, a chance to reason with C’Thun’s dominance on a more spiritual level.

“I think that there is some kind of event that involves NPCs assisting in this fight. I mean there's such thing as a design flaw that would, for example, make C'Thun too difficult to kill, but I don't think anyone on earth would be dumb enough to release content that isn't even remotely close to doable,” wrote a poster named Xavier on the Elitist Jerks forum at the height of the controversy. “I mean really, C'Thun is a God, it would be quite stupid if he was killable by 40 people.”

All that desperation mercifully came to an end on April 26, 2006. Blizzard decisively responded to all the hatred and confusion, and scaled back C’Thun’s weaponry—gutting the ridiculous challenge of the encounter and making him a lot more approachable. Nihilum, a top European guild, secured the world first the same day as the patch, as did everyone else when they made their subsequent post-nerf attempts. Suddenly, after two months of angry deaths, C’Thun was a lot less scary. It was a slightly underwhelming finale for a boss that had rightfully earned its own cult of personality. Failure is one of the few people who believes that C’Thun was killable in his previous state, and naturally felt a little betrayed when all the challenge suddenly evaporated.

A guild celebrates in front of C'Thun, via Shivtr.com.

“C’Thun was legitimately bugged, but they nerfed him too far and made it a joke of a fight,” he says. “Also they nerfed it at the start of the North America raid reset so European guilds had the first shot at it. They went in there, it took two hours and they killed it, then we went in there, it took us two hours and we killed it. It was still a top 10 kill but that was very frustrating.”

Failure is, of course, speaking from a highly competitive perspective. For the raiders who were simply tired of being annihilated, the added regulation on C’Thun’s powers was pretty cathartic.

“I hated the fight immediately because of the INSTANT WIPE BEAM OF GREEN DEATH. Then you had literally 15 minute run back to his room, and if the trash mobs respawned, another 30-45 minutes to clear,” says Scott Smith, who raided as Norther in a guild called Malevolence. “Shit was such a nightmare it tainted the whole outlook on the fight. Practically the whole guild hated C'Thun, regardless of mechanics. So when it finally got nerfed it was a huge sigh of relief. Finally we kill this fucking thing! And we did, and loot was had.”

He’s right: nobody should advocate for monolithic, impossible, nose-to-grindstone, life-ending raid bosses, but there is something kind of magical about pre-nerf C’Thun that you can’t quite find in World of Warcraft anymore. Shortly after C’Thun was killed Blizzard announced all raids going forward would be tuned for 25-player groups. By Wrath of the Lich King, everyone, even the iconic Lich King, could be attempted in 10 and 25 player groups in both casual and heroic modes. In Warcraft today I can join a Raid Finder group and kill Archimonde with a bunch of strangers I’ll only meet once. Yes hardcore and super-hardcore pathways still exist for players, but the indomitable mystery of C’Thun couldn’t exist in the same way today. There’s a big difference between a boss being unkillable, and the hard-mode version of a boss being unkillable while his normal version dies every night to pick-up groups.

Blizzard has taken great strides in their balancing and tuning since C’Thun, and they very seldom release a broken encounter anymore. In that cleanliness, World of Warcraft has gotten a little predictable. C’Thun’s reign of terror was exciting. Alone, in the bottom of the temple, with an incomprehensible horror that shrugged off all of your offense. Generally you don’t want a community of players at their wit’s end, speculating that maybe there’s a backdoor mechanic allowing NPCs to offer assistance—but that’s still kind of awesome, right? In 2016 you’d never find yourself searching for adventure game logic in an MMO, but in the depths of C’Thun’s delusions, that actually made sense.

“What was interesting about C’Thun was it instantly weeded out people who couldn’t pay attention and didn’t understand, if you didn’t spread right? Instantly dead and probably killing others, didn’t move from the eye beam? You’re dead,” says Sokur.

With the recent shuttering of Nostalrius , (a private server that captured WoW in its infancy,) there’s been a lot of fan outcry elegizing the death of Blizzard’s primitive wild-west worldbuilding. C’Thun could be the mascot for that era: a completely unreasonable encounter that maybe one percent of the total player-base will ever see. You don’t lose in World of Warcraft. Every boss falls. Deathwing, Illidan, The Lich King, Yogg-Saron, Archimonde, Onyxia. The titans of this universe are propped up to be put on farm status. It’s the necessary letdown we need to accept in order to make this game work. It’s the only way to give millions of players a happy ending.

But C’Thun? C’Thun beat the odds. It was the one time that cycle of destruction didn’t come to pass, and Azeroth’s mightiest heroes cowered against the primal powers of the Old God. It’s good to feel big, but sometimes it’s even better to feel small.