|Release date||19 August 2010 (Update)|
|Combat level||Varies [[Combat level::All Combat level::Varies| ]]|
|XP per kill||Varies|
|Examine text||A demon used to barking orders to its warriors.|
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.
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. Upon entrance to the boss room, Yk'Lagor is bound to the ground and surrounded by a barrier that appears to be held by several Mysterious mages in the room. 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 killing the rest of the mages with a single, powerful blast of magic that will not target any player. 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.
|Novite battleaxe||1||Random||Not sold|
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|Kal'gerion notes (part 4)||1||Common||Not sold|
|Mysterious chronicle||1||Common||Not sold|
- 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 Nex, troll 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.