Kromog is a massive magnaron found inside the Blackrock Foundry. He serves as one of the raid's many bosses, and the final boss of the Black Forge wing.
The magnaron are mysterious in their ways, ancient and inscrutable. Miners excavating an expansion to the Foundry, in support of the Iron Horde's massive production needs, were horrified to unearth a chamber containing a living magnaron. To their astonishment, Kromog began to assist in their endeavors, and now uses his massive stone fists to hammer out the gigantic plates needed for the Iron Horde's dreadnaughts and siege machinery.
The massive magnaron Kromog stands immobile overlooking a ledge as he assaults players with his fists and the very stone beneath them. Many of Kromog's mighty attacks create Reverberations, and at 30% remaining health, Kromog gains the effect of Frenzy.
Damage Dealers
Allow yourself to be gripped by a hand created by Rune of Grasping Earth in order to avoid critical damage from Thundering Blows.
Free yourself from Rune of Grasping Earth once Thundering Blows is complete, then help free other players who are still grasped.
Healers
Allow yourself to be gripped by a hand created by Rune of Grasping Earth in order to avoid critical damage from Thundering Blows.
Players gripped by Rune of Grasping Earth eventually become crushed to death, due to increasing damage over time.
Tanks
Allow yourself to be gripped by a hand created by Rune of Grasping Earth in order to avoid critical damage from Thundering Blows.
Kromog's Slam ability deals less damage the farther away players are from his fists when they slam onto the ground.
Kromog's normal attacks cause Fists of Stone, inflicting heavy damage which may be shared by up to 2 targets.
If Kromog is not being tanked, he will continually cast Stone Breath.
Abilities
Warped Armor — Reduces the movement speed of the target by 15%. Also increases physical damage taken by 20%. This effect stacks up to 5 times.
Fists of Stone — Kromog's melee attacks trigger this effect, which inflicts 353925 to 372075 Physical damage split evenly between enemies, up to 2 targets within 15 yards.
Stone Breath — Deals 37644 to 39576 Nature damage to all enemies every second. If there are no valid targets in melee range, Kromog will continue to breathe until he finds one.
Slam — Kromog strikes the ground beneath his primary target, dealing up to 780000 Physical damage to all players, reduced based on their distance from the impact point.
Rippling Smash — Kromog smashes the ground violently, causing a cascading eruption that inflicts 214500 to 225500 Nature damage to those within its wake.
Rune of the Grasping Hand — Kromog places a mighty palm on the ground, summoning the very stone from the earth. Fists of stone grasp at players, inflicting 12168 to 12792 Nature damage per second, but shielding them from Physical damage and holding them to the ground. The damage increases over time.
Thundering Blows — Kromog smashes his fists repeatedly, inflicting 126750 to 133250 Physical damage to all players every second, knocking them high into the air.
Rune of Crushing Earth — Kromog bends the earth to form two outstretched hands. These hands will slam together, inflicting 195000 to 205000 Nature damage to enemies on contact, stunning them for 5 sec.
Reverberations — The clamorous impact of Kromog's fists causes sound reverberations to amass, inflicting 146250 to 153750 Sonic damage to enemies with which they come into contact and dissipate.
Shattered Earth — Deals 58500 to 61500 Nature damage to 4 random targets.
Frenzy — Damage increased by 20%. Attack Speed increased by 20%. Abilities are cast more frequently. Kromog will gain the effects of Frenzy at 30% remaining life.
Rune of the Stone Geyser — Kromog channels the earth, causing massive pillars to erupt for 146250 to 153750 Nature damage. These pillars will recede back into the earth unless shattered.
Call of the Mountain — Inflicts 1170000 to 1230000 Physical damage to enemies within line of sight.
Strategy
Please add any available information to this section.
Blackhand yells: That beast was irreplaceable. Where are the attackers now? I want them dead. DEAD!
Unused quotes
Put you back into earth.
CRRRRRUSH... YOU!
Break you!
Trivia
He utilizes the same animations as Kologarn.
The rock spikes in the tunnels in the Slagworks are caused by Kromog. Upon his death, this trap will vanish.
This article or section includes speculation, observations or opinions possibly supported by lore or by Blizzard officials. It should not be taken as representing official lore.
It is possible that Kromog assumes that Blackrock Foundry is a titan facility.
Kromog
Damage Dealers
Healers
Tanks
Warped Armor 
Fists of Stone 
Stone Breath — Deals 37644 to 39576 Nature damage to all enemies every second. If there are no valid targets in melee range, Kromog will continue to breathe until he finds one.
Slam 
Rippling Smash — Kromog smashes the ground violently, causing a cascading eruption that inflicts 214500 to 225500 Nature damage to those within its wake.
Rune of the Grasping Hand — Kromog places a mighty palm on the ground, summoning the very stone from the earth. Fists of stone grasp at players, inflicting 12168 to 12792 Nature damage per second, but shielding them from Physical damage and holding them to the ground. The damage increases over time.
Thundering Blows 
— Kromog smashes his fists repeatedly, inflicting 126750 to 133250 Physical damage to all players every second, knocking them high into the air.
Rune of Crushing Earth — Kromog bends the earth to form two outstretched hands. These hands will slam together, inflicting 195000 to 205000 Nature damage to enemies on contact, stunning them for 5 sec.
Reverberations — The clamorous impact of Kromog's fists causes sound reverberations to amass, inflicting 146250 to 153750 Sonic damage to enemies with which they come into contact and dissipate.
Shattered Earth — Deals 58500 to 61500 Nature damage to 4 random targets.
Frenzy — Damage increased by 20%. Attack Speed increased by 20%. Abilities are cast more frequently. Kromog will gain the effects of Frenzy at 30% remaining life.
Rune of the Stone Geyser — Kromog channels the earth, causing massive pillars to erupt for 146250 to 153750 Nature damage. These pillars will recede back into the earth unless shattered.
Call of the Mountain 
Please add any available information to this section.
[Axe of the Stone Geyser]
[Earthbound Shield]
[Rockbreaker Warcap]
[Erupting Mantle]
[Chestguard of Allegorical Shadows]
[Chestplate of Runed Earth]
[Robes of Living Earth]
[Reverberating Bracers]
[Thundersmash Gloves]
[Slam Jammers]
[Ring of Shattered Faults]
[Stoneheart Idol]
[Ebonflame Hood]
[Sootfur Cap]
[Blacksteel Casque]
Patch 6.0.2 (2014-10-14): Added.