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For his tactics in Gnomeregan, see Mekgineer Thermaplugg (tactics).
MobSicco Thermaplugg
Image of Sicco Thermaplugg
Title Mekgineer
Gender Male
Race Leper gnome
Class Engineer, Inventor, Tinker
Reaction Alliance Horde
Affiliation(s) Independent
Former affiliation(s) Gnomeregan
Occupation Self-styled "King of Gnomeregan"
Former occupation(s) Advisor of High Tinker Gelbin Mekkatorque
Status Deceased (lore)[1]
Killable (WoW)
Companion(s) Telzo Sparkspanner (assistant)

“Usurpers! Gnomeregan is mine!”

— Sicco Thermaplugg[2]

Mekgineer Sicco Thermaplugg was once an ambitious gnomish engineer who served as the chief advisor and best friend of High Tinker Gelbin Mekkatorque. In secret, Sicco was filled with envy for Gelbin and desired the position of high tinker for himself, a lust for power that led him to become Gnomeregan's greatest traitor. When the troggs invaded Gnomeregan, Thermaplugg convinced Mekkatorque to flood the city with radioactive gas in order to kill the invaders. He secretly planned to let many of the gnomes die from the gas as well and blame the deaths on Mekkatorque. However, the radiation proved deadlier than Thermaplugg had anticipated, wiping out the majority of the gnomes and turning many of the survivors, including Thermaplugg himself, into leper gnomes while Mekkatorque led the remaining survivors into exile.

Driven completely mad by the radiation, Thermaplugg declared himself "king of the gnomes" and took control of the leper gnomes in the ruined city, still obsessed with the end goal of either ruling over the gnomish race or destroying it entirely.[3] Upon learning of his old friend's betrayal, Mekkatorque ordered Alliance heroes to kill him, but Thermaplugg eluded every attempt on his life. In the leadup to the Cataclysm, Mekkatorque rallied the gnomes and other races of the Alliance to join him in Operation: Gnomeregan, an assault that succeeded in retaking Gnomeregan's surface and ultimately led to Thermaplugg's death.


Early life[]

In his youth, Sicco Thermaplugg was the closest friend of Gelbin Mekkatorque. Gelbin helped him graduate from Gearshaft University, and when the two of them graduated together, Sicco gifted Gelbin a pair of mithril-rimmed spectacles. Gelbin wore them constantly for decades thereafter.[4]

Gelbin subsequently employed Sicco at his foundry,[4] and the two worked together on many of the inventions that launched Gelbin to fame.[5] All the while, Sicco secretly grew to resent his friend, believing that he coasted by on unpredictable "genius" while Sicco himself had to work for recognition. In reality, Gelbin considered Sicco to be one of the brightest gnomes in Dun Morogh and was always vocal about his gratitude for his friend's help. However, he also believed that while Sicco had creative ideas, he was too impatient, sloppy, and "goblin-esque" in his work. At one point the two worked together on the first siege engine prototype, with Gelbin assigning Sicco to ordnance design in the hopes that he would step up to the task. Sicco's figures proved as dangerously imprecise as ever, so Gelbin secretly reworked them before sending them off to Ironforge. In spite of this, he still allowed Sicco to take credit for the guns, simply because they were friends.[4]

For his achievements, Gelbin was ultimately elected high tinker of Gnomeregan. This infuriated Sicco, who thought that he should've had the position instead.[5] In addition to being envious of Gelbin's position, Sicco was also frustrated by how the gnomes traded away their inventions and weapons to allies instead of using them to expand the power of their nation, a failing he laid entirely at Gelbin's feet.[4][6] Unaware of his friend's true feelings, Gelbin lifted Sicco to a prominent role in the Tinkers' Court in spite of worrisome and increasingly flawed performance,[4] and he went on to serve as Gelbin's chief advisor for many years.[7]

At one point, the mekgineer Oglethorpe Obnoticus earned the respect of the Tinkers' Court by creating an unbeatable robot. Sicco stole the blueprints, created his own, giant version—the Crowd Pummeler 9-60—and set it loose in Gnomeregan. The ruling council believed Oglethorpe to be responsible and banished him from the city. The crowd pummeler remained in Sicco's possession as one of his favorite (stolen) inventions.[8]

Fall of Gnomeregan[]

Gnomeregan TCG

The irradiated city of Gnomeregan.

At the onset of the Third War, the lower parts of Gnomeregan were invaded by troggs that had been released from Uldaman. Not wanting to divert resources from the Alliance's battles in the Third War, Gelbin kept the invasion secret from the rest of the Alliance.[9][10] Years later, it would be rumored that Thermaplugg somehow knew of the trogg invasion beforehand and allowed it to happen, or that he was even the mastermind behind the entire event. These reports have never been verified, but Mekkatorque believes they could be true.[7][11][12][13] Either way, Sicco decided to use the war as an opportunity to seize Gelbin's power and prestige for himself,[6] and engineered a plan to that effect with the help of his assistant Telzo Sparkspanner.[14]

After five years of siege, the troggs breached Gnomeregan's engineering quarters, gaining access to dangerous and unstable materials that could lead to the city's destruction.[6] Gelbin was at a loss for what to do[12] and turned to Sicco for help.[5] The latter proposed a brutal plan: detonate a bomb to bathe the overrun parts of the city in lethal, radioactive gas.[6][15] He claimed to have tested the gas beforehand and to have evidence of its lethal effect on the troggs. He showed Gelbin falsified numbers on its density and volumetric weight, making it seem as though it would stay in the trogg-infested lower sections of the city and poison the invaders as they emerged from the depths while the gnomes waited safely in the upper urban tunnels, protected from the gas by Sicco's own Kleen Wind Domicilic Filters. Gelbin eventually agreed to the ploy since it seemed to be the only way out of the invasion, wouldn't require any help from the rest of the Alliance,[4] and seemed better than waiting for a disaster to destroy the city.[6] In reality, Sicco intended for the gas to anger the troggs and kill the gnomes.[16] He calculated that thirty percent of the gnomes would die—a "statistically meaningful number of corpses" that he could lay at Gelbin's feet, after which he would swoop in and defeat the troggs, prompting the gnomes to elect him as their new high tinker.[4]

When the bomb went off,[6] the gas rose to fill the entire city just as Sicco had planned, irradiating gnomes as well as troggs. Although the gas did kill troggs,[5][7] most simply shambled through it, growing wilder as they became irradiated. Meanwhile, the gnomes who sat waiting in their homes choked to death when the toxic clouds sifted through Sicco's wind filters. However, the gas turned out to be much more effective than Sicco had anticipated[4] and ended up killing nearly eighty percent of the gnomish race in a matter of days. In addition, many of the survivors were mutated into insane leper gnomes.[6][7][9][12][17]

In another miscalculation, the disaster did not cause the gnomes to turn against Gelbin as Sicco had intended; instead they continued to love and follow him as their leader.[4] The high tinker led the healthy survivors in evacuating the city and fleeing to Ironforge. According to one source, Sicco was left behind in Gnomeregan during the evacuation, trapped in the horror he had created,[6] while other sources state that he disappeared shortly after the evacuation.[7][12] Either way, the radiation twisted Sicco into a leper gnome as well and rendered him insane. He easily recruited the other leper gnomes[1] and seized control of the toxic city, installing himself as its new techno-overlord[11][12][13] and proclaiming himself the king of the gnomes.[18]

World of Warcraft[]

WoW Icon update This section concerns content related to the original World of Warcraft.

“I trusted Thermaplugg. Never did I expect that he would betray me and the entire gnomish people. And for what? Power? Wealth? All things that he would have had in time. Now we have been displaced from our home and that madman is in charge. The king of nothing....”

— Gelbin Mekkatorque[19]
Mekgineer Thermaplugg

Thermaplugg in his battle suit.

Mekgineer Thermaplugg closeup

Closeup of Thermaplugg in his suit.

Sicco ruled over Gnomeregan from the Tinkers' Court, driving a massive, cauldron-shaped prototype armor suit[4] and surrounded by leper gnome and trogg minions who were numerous and crazed enough to defend their king against any intrusion from the surface world. With the cunning to destroy everything around him and no thought for his own life, Sicco was dangerous enough that even the monsters of Gnomeregan came to fear him.[18]

He continued working on new inventions but was as impatient as ever, rushing each new invention into the field and moving on to the next project without testing their safety and effectiveness. The Electrocutioner 6000 was his first attempt to harness electricity as a weapon via a super-charged mechano-tank, but only a single soldier survived piloting it.[20] He also personally guarded the blueprints to a new "super rig" in a safe in the Tinkers' Court.[21] Thermaplugg was in contact with the Dark Iron clan, as shown by the presence of Dark Iron Agents and the Dark Iron Ambassador in Gnomeregan, and the Dark Irons were involved in the making of the aforementioned rig.[22] There is evidence that Sicco may have been working on a cure for the leper gnomes' condition.[23]

Guilt and grief over the loss of Gnomeregan weighed heavily on Gelbin, but not as much as confusion over his old friend's betrayal: the gnomes as a race had always relied on each other, and it was inconceivable for a gnome of all races to harm his own kind in search of power. Gelbin later reflected that Gnomeregan had fallen because he'd trusted his friend to be a friend, or at least to be a gnome, and that Sicco was neither.[4] As part of efforts to retake the capital, Gelbin ordered Alliance adventurers to kill Sicco.[19] A band of heroes took up the mission and returned with a tale of victory. However, after analyzing their claim, Gelbin realized that the mechanized overlord they'd defeated in Gnomeregan was likely nothing more than a clever facsimile of Thermaplugg, and that defeating his nemesis would take a more robust approach.[12] Some goblins also wanted to send adventurers to fight Thermaplugg in order to get their hands on the super rig blueprints.[21][22]

Operation: Gnomeregan[]

“No! No, no, NO!!! I won't allow you into my kingdom, usurper! I WON'T ALLOW IT!”

— Sicco to Gelbin during Operation: Gnomeregan[15]
Irradiator 3000

The Irradiator 3000.

After years of planning, Gelbin put into action Operation: Gnomeregan, an assault to liberate the city and bring the real Sicco to justice. In response, Sicco prepared his own forces and deployed "Brag-Bots" to spread his propaganda in Dun Morogh.[12]

After capturing the entrance, Gelbin's forces headed for Thermaplugg in the heart of the city. In response, Sicco sent forth hordes of troggs led by Gasherikk and leper gnome soldiers led by Commander Boltcog. When Gelbin's forces continued to push through, Sicco revealed an ace: the Irradiator 3000, a device similar to the original radiation bomb that had poisoned Gnomeregan but twenty-six times more powerful. It began a ten-minute countdown to explosion until Sicco realized his underlings had left the factory setting on and intervened, reducing the timer down to ten seconds and forcing Gelbin's forces to immediately teleport back to the safety of Tinker Town in Ironforge. However, Gelbin stated that with the surface of the city retaken, Thermaplugg had only bought himself time.[15]

Cut Short[]

WoW-novel-logo-16x62 This section concerns content related to the Warcraft novels, novellas, or short stories.

“You don't deserve a quick death, Sicco. You deserve a long, miserable existence in a dark hole, surrounded by filthy monsters. In fact, you have created your very own prison right here. Better than any I could have built for you. You definitely outdid me on this one. Congratulations. Besides, if you do survive, I can't think of anybody I'd rather have leading these beasts than one of their own. Enjoy your remaining time in jail, my friend. Your sentence is almost over.”

— Gelbin leaving Sicco for dead[4]

As the push to retake Gnomeregan continued, Sicco set a trap in Gelbin's old living quarters in sector 17 by tying a tripwire to the high tinker's old spectacles, which had been left behind during the original evacuation. After his troops did a sweep of the area, Gelbin headed into the quarters alone and unarmed and picked up the glasses, realizing too late that it was a trap. Sicco closed the doors to the room and sent in three troggs to kill the high tinker while gloating via intercom about how his death would devastate the gnomes. Gelbin used his surroundings to hold off the troggs and kept talking to Sicco in order to keep him distracted, mockingly pointing out how his genocide plan hadn't resulted in him winning any elections. In response, Sicco expressed his frustration over how the gnomes had gone against all "logic" by staying loyal to Gelbin even after the fall of Gnomeregan, and he exclaimed that he was glad that the gas had killed as many as it had since the gnomes "needed this purge".

By exploiting the sloppy way in which Sicco had engineered the trap, Gelbin managed to dispatch the troggs. Before the high tinker could escape, Sicco arrived with dozens of more troggs to deal with him personally, driving a new, agile, human-sized battle suit; he explained that the previous suit had proven too bulky, and that the king of the gnomes should see eye-to-eye with the other rulers of the land. He and Gelbin exchanged words, with Sicco expressing bitterness over how he'd never received the recognition he thought he deserved while working under Gelbin. In response, Gelbin revealed how he'd allowed Sicco to take credit for the siege engine guns that Gelbin had secretly reworked because of their friendship, and for a moment the surprised Sicco looked more like the bright young gnome that Gelbin had once befriended. However, the moment passed, Sicco declared that this was only an example of Gelbin's weakness, and prepared to kill him.

Gelbin had a backup plan: he took advantage of the trap mechanism he'd repurposed and released a tensely wound spring that had been holding up more weight than it should have been, instantly decapitating every trogg in the room and cutting Thermaplugg's suit in half, severing his legs from his body. However, Sicco survived due to the suit cauterizing his wounds, likely with minimal blood loss. Gelbin decided to leave him for dead so that his suffering would be prolonged, citing it as an appropriate punishment for his crimes against the gnomes. He decided that if the rats or the troggs didn't kill Thermaplugg, then he'd think of no one better to lead the troggs than one of their own.[4]


Cataclysm This section concerns content related to Cataclysm.

Although Operation: Gnomeregan didn't succeed in retaking the city itself, it allowed the gnomes to establish New Tinkertown at its entrance. Thermaplugg remained in hiding in Gnomeregan and sent his minion, Razlo Crushcog, and a force of leper gnomes to harass Mekkatorque's forces on the surface in order to prevent them from rebuilding and finishing their reclamation of the capital.[24][25] The gnomes later killed Crushcog with help from their dwarven allies; with his defeat, Sicco couldn't afford to send any more of his followers to the surface, and Gelbin stated that the mekgineer's defeat was imminent.[26]

The G-Team, an elite group hired by the high tinker to retake Gnomeregan, later recruited adventurers to kill Sicco himself,[27] and they finally managed to defeat the mekgineer. The unique equipment Sicco carried, such as the Electromagnetic Gigaflux Reactivator, was returned to Tinker Town for safekeeping.[1]


Shadowlands This section concerns content related to Shadowlands.
Mord'al Eveningstar

Mord'al Eveningstar, rumored to be Thermaplugg's soul.

Some say that Mord'al Eveningstar, a tiny Mawsworn known for torturing the smallest souls in the Maw, was known in life as "Thermaplugg".[28]


World of Warcraft[]

Main article: Mekgineer Thermaplugg (tactics)#Quotes
Main article: Operation: Gnomeregan (quest)#Notes

Cut Short[]

WoW-novel-logo-16x62 This section concerns content related to the Warcraft novels, novellas, or short stories.
  • "Gelbin, do you have any idea what your death will do to the gnomes? They have kept you at the helm in spite of everything I've done to discredit you. The little fools love their high tinker. Your death is going to rip their hearts out."
  • "Who could have calculated that the gnomes would still follow you after I had practically painted your hands with their blood? That they would disregard logic and act like a bunch of weepy, emotional night elves? I'm glad the gas did what it did! The gnomes needed this purge!"
  • Sicco: "It is only fitting that the king of the gnomes see eye to eye with the other rulers of the land. A difficult concept for a puny failure like you to grasp, I know."
Gelbin: "The king of the gnomes, huh? So you've given up on winning an election, I presume. That's probably for the best, since the electorate might have a hard time voting for a candidate who's not a gnome."
Sicco: "I think begging for scraps at the dwarven table has driven you a little batty, Gelbin. Not a gnome? I am ten times the gnome you will ever be! While you sat back and coasted on your phony, unpredictable 'genius,' I was the one who had to actually work for recognition."
  • "The gnomes should be dominating this land with our unstoppable weapons, not trading them away to imbecilic allies. That's what goblins are for!"

Notable servants[]

In the RPG[]

Icon-RPG This section contains information from the Warcraft RPG which is considered non-canon.
Sicco Monster Guide

Thermaplugg in the Monster Guide.

Mekgineer Sicco Thermaplugg was once a brilliant and wise tinker, who despite being incredibly frail even at a young age, was destined to be High Tinker. He cunningly laid the way to the seat, charming people to his side and cranking out one great invention after the next. He worked unceasingly toward his goal, for Thermaplugg planned not only making High Tinker, but also becoming the gnome's first true king in over four hundred years. He envisioned a great kingdom out of Gnomeregan, carved out of the entire western half of Dun Morogh, even if it meant relocating the nearby dwarven communities in the name of progress. Nothing would stop him! However, his closest friend, Gelbin Mekkatorque, ruined all of his goals when the council of tinkers decided that Thermaplugg was too ambitious and chose Mekkatorque instead.[30]

It was his idea that, during the trogg invasion, the gnomes shut themselves from the world. Thermaplugg claimed that the world outside didn't need to be bothered by gnomish problems, for he had an idea that would both destroy the image of Mekkatorque and win him the throne. After weeks of debate, he convinced Mekkatorque to flood the halls of Gnomeregan with radiation via a bomb, thus killing the troggs. If a few gnomes died in the process, he stated, it would be a worthy sacrifice for saving the entire race.[30]

However, due to reasons even Thermaplugg can't remember, he found himself locked inside Gnomeregan when the bomb release began. Despite his age and frailty, he did not die. Some speak that it was his ambition that saved him, while others say he hid and suffered the least of the poison. Despite this, he lived and mutated into a leper gnome. The radiation killed more gnomes than troggs, and many other gnomes in Gnomeregan's walls also suffered from radiation and became leper gnomes. However, in the ensuing chaos, Thermaplugg had begun calling himself a king. To this day he rules over the leper gnomes and continues fighting the troggs. He controls his land with a tyrannical fist, destroying outsiders as rapidly as any other enemy.[30]

He keeps to himself most of his time since becoming king of Gnomeregan, working on insane world-conquering inventions. Thankfully, few if any will ever see the light of day. Paranoid beyond rational thought, Thermaplugg destroys anything that disturbs his work, even his own leper gnome servants. Recently, however, he opened up negotiations with the Dark Iron dwarves, allowing them use of Gnomeregan's tunnels in exchange for a part of Ironforge to call his own. No one knows what may become of this alliance, but it won't be good.[30]

Rumors say that the Dark Iron dwarves and Mekgineer Thermaplugg, head of the leper gnomes in fallen Gnomeregan, seek an alliance.[31][32]

In Hearthstone[]

Hearthstone This section contains information exclusive to Hearthstone and is considered non-canon.

Thermaplugg appears as a legendary card in the Goblins vs Gnomes expansion for Hearthstone. His flavor text reads: He was obsessed with explosives until he discovered knitting. Now he yells, “SWEATERS! MORE SWEATERS!”


Thermaplugg Without Machine

Model viewer image of Sicco without his machine.

  • In A IconSmall Gnome MaleIconSmall Gnome Female [1-30] Down with Crushcog!, Gelbin states that Razlo Crushcog's defeat will cause Thermaplugg to "[quake] in his mechano-tank", but Sicco has never been depicted riding a mechano-tank in-game.
  • Under the name Mekgineer-Lord Thermaplugg, Sicco was planned to appear as the final boss of Imminent Launch, a scrapped Mage Tower challenge for stealth classes. In the scenario, he would be allied with the Burning Legion and appear in new armor riding a fel reaver, and players would have to stop him from launching a missile at the Broken Isles. The scenario did not make it out of the PTR for patch 7.2.[33][34] Endgineer Omegaplugg may be a leftover from this.
  • It was originally stated that the Heritage of Gnomeregan questline in patch 8.2 would go into the history of Thermaplugg's remaining family.[35] The questline seen in the final game features nothing of the sort, instead centering on Thermaplugg's lieutenant Telzo Sparkspanner.
  • Thermaplugg is voiced by Dave Mallow.
  • His first name is presumably a wordplay on "sicko", a mentally ill or perverted person, especially one who is sadistic.


  1. ^ a b c World of Warcraft: Exploring Azeroth: The Eastern Kingdoms, pg. 64
  2. ^ Mekgineer Thermaplugg (tactics)#Quotes
  3. ^ Blizzard Entertainment 2011-06-15. Leaders of the Alliance and Horde -- Gelbin Mekkatorque. Archived from the original on 2022-01-15.
  4. ^ a b c d e f g h i j k l m Cut Short
  5. ^ a b c d Ultimate Visual Guide, pg. 84
  6. ^ a b c d e f g h World of Warcraft: Chronicle Volume 3, pg. 114
  7. ^ a b c d e World of Warcraft: Game Manual, pg. 175
  8. ^ Crowd Pummeler 9-60#Dungeon Journal
  9. ^ a b Game Guide: Gnome
  10. ^ World of Warcraft: Chronicle Volume 3, pg. 56
  11. ^ a b World Dungeons: Gnomeregan
  12. ^ a b c d e f g Operation: Gnomeregan#First announcement
  13. ^ a b Gnomeregan - Game Guide. Archived from the original on 2013-11-21.
  14. ^ a b A IconSmall Gnome MaleIconSmall Gnome Female [50-70] A Signal in Storm Peaks
  15. ^ a b c A [75] Operation: Gnomeregan
  16. ^ Grubbis#Adventure Guide
  17. ^ World of Warcraft: Exploring Azeroth: The Eastern Kingdoms, pg. 62
  18. ^ a b Mekgineer Thermaplugg (tactics)#Adventure Guide
  19. ^ a b A [35D] The Grand Betrayal
  20. ^ Electrocutioner 6000#Adventure Guide
  21. ^ a b H [35D] Rig Wars
  22. ^ a b N [30D] A Fine Mess
  23. ^ Inv potion 22 [Vial of Green Goo]
  24. ^ A IconSmall Gnome MaleIconSmall Gnome Female [1-30] The Fight Continues
  25. ^ A IconSmall Gnome MaleIconSmall Gnome Female [1-30] Crushcog's Minions
  26. ^ A IconSmall Gnome MaleIconSmall Gnome Female [1-30] Down with Crushcog!
  27. ^ B [10-30D] The G-Team
  28. ^ Inv mawguardpet red [Mord'al Eveningstar]
  29. ^ A IconSmall Gnome MaleIconSmall Gnome Female [50-70] The Gnome Behind the Trogg
  30. ^ a b c d Monster Guide, pg. 168
  31. ^ Dark Factions, pg. 8
  32. ^ World of Warcraft: The Roleplaying Game, pg. 146
  33. ^ Wowhead / WoWDB
  34. ^ Wowhead / WoWDB
  35. ^ World of Warcraft 2019-04-11. Rise of Azshara Content Preview (23:08). YouTube. Retrieved on 2019-08-09.
Preceded by:
Gelbin Mekkatorque
Ruler of Gnomeregan
Succeeded by: