Core Keeper boss guide: How to find and beat every giant monster

Core Keeper boss fights
(Image credit: Pugstorm)

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(Image credit: Pugstorm)

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Core Keeper bosses are the toughest challenge in the new Early Access co-op survival sandbox. For a tiny pixelated adventurer, bosses can pose a major threat, but with the right preparation and a few winning strategies you'll be able to overcome them and use their gems to power up the Core.

The first three bosses you'll face in Core Keeper are Glurch the Abominous Mass, a giant orange slime that spawns close to the starting area, Ghorm the Devourer, a massive insect that uses the underworld as its own private race track, and The Hive Mother, a fleshy, acid-spitting nightmare surrounded by tough organic walls. There's a fourth boss, Azeos the Sky Titan, which can only be found and beaten once you've defeated the first three and activated the Core. There are also optional bosses: Malugaz the Corrupted can be summoned in the Forgotten Ruins and Ivy the Poisonous Mass can be found in the Azeos Wilderness biome.

Below you'll find our Core Keeper boss guide, including how to locate them and the best ways to beat them.

Glurch the Abominous Mass

Glurch the Abominous Mass

Core Keeper boss

(Image credit: Pugstorm)

You should have:

  • Copper armor
  • A tin sword
  • A few crude bombs
  • A shovel
  • Food that boosts speed or damage

Glurch is located pretty close to your starting point. As you explore further from the Core you'll occasionally hear a distant thudding. That means you're close to Glurm. Look for areas with high concentrations of orange slimes, and he's bound to be nearby in a large chamber.

Glurch is a big blob with a leaping attack, a bit like Spelunky's Olmec, and when you get within a few blocks of him he'll pop up into the air and try to land on you. He's capable of smashing through solid rock, so don't think ducking into a tunnel will save you. That said, if you flee far enough away he'll retreat back to his starting spot.

Don't get within 3 blocks of Glurch until you're ready to fight, or he'll aggro. Prepare by clearing Glurch's chamber of as much slime as you can using your shovel, because stepping in slime will slow you down. If there are any hostile spiky slimes hanging around, kill them first too.

Once Glurch starts jumping, either move away or run directly under him while he's in the air. It's very important you don't let him retreat all the way back to the rune circle he sits on, because he'll start healing the damage you've done. Each time he lands, rush up and hit him with your tin sword a couple times, then fall back before he leaps again. Crude bombs can also damage him, but only slightly. 

As long as you move quickly and don't let him retreat back to his starting spot, you should be able to manage that battle without too many problems.

Ghorm the Devourer

 Ghorm the Devourer 

(Image credit: Pugstorm)

You should have:

  • 50 spike traps
  • A copper shovel
  • Torches
  • Crude bombs
  • Swift ring

Finding Ghorm isn't all that difficult. Just start tunneling in any direction from the core and you'll eventually run into Ghorm's wide, slime-filled tunnel. That's because Ghorm is a mobile boss: It's constantly moving in a huge circle that surrounds the Core. Below you can see Ghorm's massive circular tunnel running around my map.

(Image credit: Pugstorm)

The real problem is stopping Ghorm. Even if you do some damage as it rushes past, it won't stop and by the time it circles around the map again it will have completely healed. Following Ghorm is difficult, too, because it leaves a slime trail behind it, and walking through slime slows you down.

The easiest way I found was using spike traps. Mine 50 units of tin ore in the Clay Caves, smelt it, and craft 50 spike traps at your crafting bench. Keep in mind: these traps will kill Ghorm almost instantly but the traps will be destroyed.

(Image credit: Pugstorm)

Head to Ghorm's tunnel and wait for it to pass by. Then quickly run into the tunnel and set your traps down in the middle of the tunnel. Kill any nearby slimes so they don't activate the traps before Ghorm completes its circle and returns.

If you don't want to use so many traps, another method is to clear slime from a long section of the tunnel with your shovel, then run ahead of Ghorm as it approaches, dropping as many bombs (not crude bombs, the bigger ones) in its path. 

Wearing two swift rings and eating foods like a hearty pepper wrap will increase your movement speed enough that you can keep ahead of him. Once Ghorm's health meter drops below 50 percent, it will stop running its tunnel circuit and come directly after you. Sidestep when it charges and uses a weapon to strike it as it runs past. It will keep turning and coming at you, so you can drop more bombs in its path and strike its side while it passes.

The Hive Mother

 The Hive Mother 

(Image credit: Pugstorm)

You should have:

  • Flintlock musket
  • Healing potions
  • Iron or carapace armor
  • Spike traps
  • Copper shovel

The best way to find The Hive Mother is by using the Glurch statue at the core. There you can craft a Hive Mother beacon that'll add an icon on your map showing her location, provided you've already defeated Glurch.

Once you know where she is, you'll need an iron pickaxe, preferably two, to tunnel your way into her chamber, which is surrounded by durable larva walls.

Once you're in her chamber, she won't attack unless you attack her. Kill any larva or other enemies in the chamber and dig up any hive spike traps or acid blobs with your shovel.

The Hive Mother's attack is a powerful acid spit that targets you from above. When you see a target marker appear on your character, you need to move. Even if the acid misses you it'll remain on the block it lands on, and walking through it will hurt you. It can be removed with a shovel, but that's hard to do during the fight. The Hive Mother also summons minions from five spots around her, which will rush to attack you.

There's a good way to cheese this fight, which is to dig a long tunnel into one of the walls of the chamber directly across from the boss. Line it with spike traps that will kill any creatures that enter the tunnel during the fight. If you stand in the tunnel so you can still see the Hive Mother's body, but not her mouth, she won't spit acid. With the flintlock musket, you can shoot her from the tunnel. 

It will take a few minutes, but it's an easy way to wear down her health while staying out of spitting range, and the narrow tunnel will make sure minions all approach from the same direction.

Another option is to build walls around the spawn points of Hive Mother's summons before the fight starts. The spots appear as five circular regions scattered around her:

If you wall those areas in, the minions won't be able to attack you and you can focus melee or ranged attacks on the Hive Mother while moving around to avoid her acid attacks.

Azeos the Sky Titan

 Azeos the Sky Titan 

(Image credit: Pugstorm / GamingWithDaOpa on YouTube)

You should have:

  • Scarlet Armor
  • Scarlet Sword
  • Healing potions
  • Scarlet Pickaxe and shovel
  • Shield
  • Bombs

Finding Azeos is a pretty complex undertaking. First you need to have defeated the first three bosses and used their gems in the boss statues to power the Core. Speaking to the Core will tell you to touch the Great Wall, the impenetrable barrier that lies further out in the world.

Once you've tunneled out and touched the Great Wall, return and speak to the Core again. It will give you a direction to tunnel towards (north, southwest, etc) which will lead you to a new biome, Azeos Wilderness. But to find Azeos the Sky Titan, you'll need to craft two items: a scanner showing his location on the map and a "large shiny glimmering object" (that's really what it's called) that summons him.

I haven't faced (or even found) Azeos myself yet but the video below from GamingWithDaOpa will show you its attacks. Azeos uses power beams that cross the map in different directions or close in a circle around you. You can try dodging them but if you have a shield equipped you can also hold down the space bar to negate most of the damage.

Azeos also summons big blue crystals that heal him. These need to be quickly destroyed so forget about hitting them with a weapon and place bombs next to each crystal as they appear. A single bomb will destroy the crystal. While blocking the beam attacks and destroying crystals, use melee attacks with your scarlet sword to defeat Azeos. 

Malugaz the Corrupted

Boss 5: Malugaz the Corrupted

(Image credit: Pugstorm / Serroh on YouTube)

You should have:

  • Scarlet sword or better
  • Fireball staff
  • Lots of healing potions
  • Lots of food
  • Shield
  • Swift Feather

Malugaz the Corrupted is a hidden boss in Core Keeper. But even if you didn't know he existed, you've probably been collecting an item needed to summon him. You can also fight him before you tackle Azeos the Sky Titan, if you prefer.

Cavelings in the Forgotten Ruins sometimes drop blue crystal skull shards. When you have 10 shards, put them in your hotbar and right-click to create a crystal skull. The next challenge is finding Malugaz's summoning spot. It'll be somewhere in the Forgotten Ruins biome, typically in one of the larger underground fortresses where there are a lot of cavelings and a number of rooms with green, unbreakable floors that show up on your map. 

Malugaz's summoning spot is in a semi-circular chamber with a skull rune on the floor in the center. Before you summon him clear the chamber of pillars and other obstructions to give yourself room to move. Placing the crystal skull on the skull rune will summon Malugaz. 

The video embedded below, created by Serroh on YouTube, shows how to find Malugaz and how to beat him. There's also a longer battle with some analysis from AllFunNGamez here.

Malugaz is a two-stage boss. Initially he'll teleport around, throwing fireballs and igniting areas on the floor that deal fire damage. If there's too much fire to approach him for melee, circle and hit him with ranged weapons like the fireball staff. When you can get in close, hit him with your best melee weapon. Dashing is important to avoid his fireballs and so have a swift feather equipped. Alternately, equip a wooden shield and hold space to block his attacks.

Once his health bar is depleted his armor will shatter and he'll gain another full health bar. Instead of throwing fireballs he will perform a dash-punch combo. Use your dash to avoid being hit and keep avoiding fires set on the floor, keep your distance with ranged attacks and hit him with melee weapons when he teleports close to you. If you leave the chamber during the fight, Malugaz will regain his health, so you can't kite him around to other parts of the map.

Ivy the Poisonous Mass

Boss 6: Ivy the Poisonous Mass

(Image credit: Pugstorm / GamingWithDaOpa on YouTube)

You should have:

  • Healing potions
  • Scarlet sword or better
  • Movement buffing foods
  • Remedaisy necklace

Ivy is a boss located in the Azeos Wilderness biome. Finding her is extremely tricky and may take a lot of tunneling and exploring of the biome. Look for any areas with a high concentration of pink poison slimes.

Ivy bears a lot of resemblance to Glurch since they're both giant slimes whose primary attack is leaping into the air and trying to land on you. In addition to the floor slime slowing you down, the pink slime in Ivy's area is also poisonous, which will reduce your healing rate by 75% for 30 second when you step in it. If you can find a remedaisy necklace, which are occasionally dropped by poisonous slimes, it will render you immune to poison which will be a major help in the fight against Ivy.

The video below from GamingWithDaOpa on YouTube shows you where Ivy was found and how she attacks.

In addition to the leap, Ivy also has a secondary attack, which is to rain down slime around her. The spots the slime will land are targeted with red circles beforehand, so you have a second or two to move before the attacks hit. Ivy will signal this attack by stopping her leaps and growling. 

When Ivy is at low health she will no longer pause between leaps and will start leaping much faster.

You best bet is to handle Ivy similarly to Glurch, by using any movement buffing items or food you have to avoid being crushed and hammering away with a melee weapon when she lands. Dashing can also help you avoid getting jumped on and to get you out of the path of her slime rain.

Christopher Livingston
Staff Writer

Chris started playing PC games in the 1980s, started writing about them in the early 2000s, and (finally) started getting paid to write about them in the late 2000s. Following a few years as a regular freelancer, PC Gamer hired him in 2014, probably so he'd stop emailing them asking for more work. Chris has a love-hate relationship with survival games and an unhealthy fascination with the inner lives of NPCs. He's also a fan of offbeat simulation games, mods, and ignoring storylines in RPGs so he can make up his own.