For the music track, see Yk'Lagor the Thunderous (music track).
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Yklagor icon

Yk'Lagor the Thunderous is the final Dungeoneering boss monster encountered on the occult floors. He is found on floors 45 to 47 of Daemonheim. A Dungeoneering level of 89 is required to fight him. He is a high-ranking Kal'Gerion demon and one of Kal'Ger the Warmonger's generals.

When Bilrach used portal magic to contact the Kal'Gerions, Yk'Lagor was one of the demons who broke through the portal and fought Bilrach's forces. During the battle, he toppled and taunted a behemoth.

The fight

Unlike other bosses who are immediately ready to fight when the player enters the room, Yk'Lagor must first be freed before he can be fought. In his room, there are eight mysterious mages that are subduing Yk'Lagor with a magical barrier. After attacking four of the mages, the demon will roar "My turn!" and break free from the barrier, causing the entire dungeon to shake and the ensuing shockwave will kill the remaining mages; the shockwave does not harm the player(s) at all. Immediately afterwards, he begins the battle with his magical drag attack.

Yk'Lagor's standard melee attack involves slashing the player if the player is standing in melee-range. The demon will attack with a fire based magical attack if no players are next to him which can drain prayer points and ignores protection prayers.

Yk'Lagor has two powerful special attacks which he alternates between. As mentioned above, he uses a magical drag attack when he shouts "Come closer" and pulls the players across the room, healing 15% of his health per player dragged in. This attack will stun the player, drain their prayer points and disable and prayers they had active. The attack can be avoided by hiding behind any of the four pillars in the boss room. Use Freedom if caught.

His second special attack is an earthquake that is indicated when he shouts "This is..." before jumping into the air, followed with a scream of "TRUE POWER" when he lands and cracks the floor. This attack can deal over 12,000 typeless damage to all players who are not behind the pillars.

Gatestone teleport, Group Gatestone Teleport, and Gatestone 2 teleport can only be used if standing behind one of the pillars. Attempting to teleport from anywhere else in the room gives the message "You can't teleport here". Thus, gatestones cannot be used to evade his special attacks.


Yk'Lagor's special attacks can be avoided by running behind a pillar as soon as the text appears above his head or you hear his voice. To hide more easily from the boss's special attacks, it is recommended to use either ranged or magic.

Apart from his special attacks, Yk'Lagor will behave in a pattern depending on the players' positions. As long as one person is close to him, Yk'Lagor will use his melee attack, which is very fast and damaging.

As long as one person stands away from him, he will use his magic attack, which hits everyone in the room. You will still get hit even if you stand behind a pillar, but only if he can target a player in his range, meaning if one player is not hiding behind a pillar, all players will get hit.

Yk'Lagor's Inprisonment

Yk'Lagor trapped by a magical shield.


Yk'Lagor killing the mages.


Yk'Lagor's magical drag.


Yk'Lagor punching the ground.


Yk'Lagor's magical attack.


Level Life points
98 10500
103 15000
106 16000
109 18500


Item Quantity Rarity GE price
Novite battleaxeNovite battleaxe1RandomNot sold
Off-hand novite battleaxeOff-hand novite battleaxe1RandomNot sold
Bathus battleaxeBathus battleaxe1RandomNot sold
Off-hand bathus battleaxeOff-hand bathus battleaxe1RandomNot sold
Marmaros battleaxeMarmaros battleaxe1RandomNot sold
Off-hand marmaros battleaxeOff-hand marmaros battleaxe1RandomNot sold
Kratonite battleaxeKratonite battleaxe1RandomNot sold
Off-hand kratonite battleaxeOff-hand kratonite battleaxe1RandomNot sold
Fractite battleaxeFractite battleaxe1RandomNot sold
Off-hand fractite battleaxeOff-hand fractite battleaxe1RandomNot sold
Zephyrium battleaxeZephyrium battleaxe1RandomNot sold
Off-hand zephyrium battleaxeOff-hand zephyrium battleaxe1RandomNot sold
Argonite battleaxeArgonite battleaxe1RandomNot sold
Off-hand argonite battleaxeOff-hand argonite battleaxe1RandomNot sold
Katagon battleaxeKatagon battleaxe1RandomNot sold
Off-hand katagon battleaxeOff-hand katagon battleaxe1RandomNot sold
Gorgonite battleaxeGorgonite battleaxe1RandomNot sold
Off-hand gorgonite battleaxeOff-hand gorgonite battleaxe1RandomNot sold
Promethium battleaxePromethium battleaxe1RandomNot sold
Off-hand promethium battleaxeOff-hand promethium battleaxe1RandomNot sold
Primal battleaxePrimal battleaxe1RandomNot sold
Off-hand primal battleaxeOff-hand primal battleaxe1RandomNot sold
Kal'gerion notes (part 1)Kal'gerion notes (part 4)1CommonNot sold
Mysterious chronicleMysterious chronicle1CommonNot sold


Yk'Lagor Future

Yk'Lagor's initial concept art. He has since been graphically updated.

Audio options icon
When bound
Audio options icon
My Turn!
When breaking free
Audio options icon
You dare steal my power?!
When killing the mages
Audio options icon
Come closer!
Before performing his magical drag
Audio options icon
This is... TRUE POWER!
When using his Earthquake special
Audio options icon
Another kill for the Thunderous!
After killing the player
Audio options icon
There is no escape!
If the player gets grabbed when trying to hide but is unsuccessful



Yk'Lagor breaking free.

  • One of the phrases the mages binding Yk'Lagor The Thunderous are chanting is "Heim crabs are awesome" backwards. (This was confirmed during the Q&A session at Runefest.)
  • With the addition of this boss, this is the first time voice acting has appeared in the game aside from the tutorial.
  • In Yk'Lagor's concept art, it is shown that his original title was "the Vociferous", which can be understood as a synonym for "the Thunderous" (a loud or noisy scream); he was also entitled as "Demon Prince".
  • Yk'Lagor introduced a trend in which his Magical Drag attack is used by many powerful monsters, not limited to Kal'Ger the Warmonger, a variation that Nextroll wizards, and Mother Mallum all use, and its sound effects are used in the Ancient ceremonial robes emote.
  • Yk'lagor used to have another special attack in which he created an area of explosions around him (similar to the ancient curse Wrath), but for some reason this was removed.
  • As shown in the video from Jagex's YouTube channel, there were 4 pillars on the northern and the southern part of the room. In the actual game, there are only 2 pillars on each side.
  • Currently there is a glitch where if a player dies at the same time as Yk'Lagor's magical drag special attack is used, the player may be dragged into the boss room from the start room.
  • Resonance used to work on his earthquake special attack.
  • Yk'Lagor is voiced by Mod Osborne.
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