Production information
Manufacturer General Systems[1]

Kallon Industries[1]

Production Year 2630[2]
Model EXT-4D[1]
Class Heavy
Cost 15,852,622 C-bills
Technical specifications
'Mech type Inner Sphere BattleMech
Mass 65 tons
Chassis SL Special[1]
Armor Fibrolyte Armorscale[1]
Engine Magna 390 XL[1]
Communications System AR-12 Sheathed Directional Beacon[1]
Targeting Tracking System DLK Type Phased Array Sensors[1]
Heat Sinks 10 double[1]
Speed 97[1] km/h
Jump Jets Chevron II[1]


BV (1.0) 1,149[3]
BV (2.0) 1,385[1][4]


The Exterminator is a BattleMech that was designed in 2630 for the most dubious, but necessary, of purposes: Head Hunting. The Exterminator was outfitted with a special Null-Signature System, heat baffles and, in some cases, a Chameleon Light Polarization Shield. These advanced systems allowed it to easily infiltrate enemy lines. Once the Exterminator breached the enemy's rear, its mission was to find and destroy as much of the enemy's command structure as possible. This mission profile included attacking mobile headquarters, field bases and command level officers. Rather than be part of the standard formation, Exterminators were attached to a regimental or higher headquarters unit, often as a fifth member of the command lance itself, before being assigned to individual units. A regiment was considered lucky to have more than one Exterminator, and it was not unusual for its parent unit to pull all assigned Exterminators and pool them for a specific mission.

It was widely believed that the Exterminator had not survived the fighting of the First Succession War as there were lances whose sole mission was to hunt down and destroy this type of 'Mech (coupled with the destruction of General Systems' primary factory on Caph in 2793). In 3007, Kallon Industries (Thermopolis, Free Worlds League), looking for a replacement for their aging Wolverine, recovered blueprints for the Exterminator and immediately modified the design so that it could be built using the technology readily available. The result was a BattleMech not only far less effective than the original, but below the capabilities of even the Wolverine it was meant to replace. Only twenty-five of these Exterminators were produced and none survived past the Fourth Succession War, making the design effectively extinct in the Inner Sphere.[5][6]

Only later was it revealed that the Exterminator still existed in ComStar's private army, the Com Guards, although even here few were of the hyper-advanced stealth models, and while the Exterminator was retained by the Clans its decidedly "dishonorable" method of fighting meant few were used. ComStar continued to produce variants which took advantage of recovered lostech, and the design was used by the Word of Blake during the Jihad.[7][8]

Weapons and Equipment[edit]

The weapons used by the Exterminator are not nearly as unique or high-tech as the onboard electronics. The primary weapons of the Exterminator are four Averell Highpoint medium lasers, two in each arm. For long-range engagements, the 'Mech also carries a Deadeye-10 LRM-10 launcher with one ton of reloads in the center torso. These weapons are backed up by a single Dinatech Mark III small laser mounted in the head for when engagements close to point-blank range and, for defense against missile attacks, the Exterminator has a Buzzsaw anti-missile system in the right torso, with one ton of ammo.[9][10]

For maneuverability the Exterminator carries six jump jets, three in the rear of the right and left torsos, allowing it to make leaps of up to 180 meters. Combined with an extralight engine these give the Exterminator the maneuverability of 'Mechs a fraction its size. Ten and a half tons of armor also give it good protection for close-quarters combat while ten double heat sinks provide enough heat management for an alpha strike.[1]


  • EXT-4A 
    The 4A is what became of the Exterminator during the Succession Wars, revived by Kallon Industries when they came across blueprints for the design in 3007. The resulting 'Mech resembles the Exterminator outwardly and carries an almost identical weapons load but otherwise is not the same machine. The only weapons change is the use of an M100 heavy machine gun with a half-ton of ammo in place of the anti-missile system. The ten double heat sinks are replaced with eleven singles, providing only adequate heat management.[1] A smaller VOX 325 standard fusion engine reduces its top speed by about 10 km/h. The armor is still identical to that of the original Exterminator, but unfortunately the Null-Signature System could not be saved. This version also made use of a Tek BattleCom communication system and Tek LOR T13d targeting system.[1] BV (1.0) = 1,067; BV (2.0) = 1,345[11]
  • EXT-4C 
    The 4C is the fully equipped stealth version of the 4D and released in the same year, including the Null-Signature System and Chameleon Light Polarization Shield. BV (2.0) = 1,602[12]
  • EXT-4Db 
    This Star League Royal version, first introduced in 2718, replaces the LRM-10 and anti-missile system with an ER large laser, two additional medium laser's, and one new heat sink, all 6 medium lasers are now torso mounted. BV (2.0) = 1,694[13][14]
  • EXT-4Db-EC 
    An early Clan Jade Falcon refit of the EXT-4Db trades the medium lasers for prototype ER medium lasers. It was popular for duels and Trials. (Note: EC is an abbreviation used by historians to designate "Early Clan" designs.)[15] BV (2.0) = 1,611[16]
  • EXT-5E 
    The 5E is a complete upgrade of the Exterminator introduced in 3060, with a new mission of closing with enemy units to deliver improved Narc pods. The 5E has an improved Narc Missile Beacon launcher and all four of its medium lasers upgraded to ER medium lasers. The jump jets have been removed from the chassis to make room for an improved C3 computer. To make up for the lack of jumping capabilities, a MASC system has been installed, allowing for an augmented speed of up to 129.6 km/h.[1] BV (1.0) = 1,253;[17] BV (2.0) = 1,532[18]
  • EXT-5F 
    This upgrade of the 5E introduced in 3074 replaces the lasers with paired light PPCs. The Narc launcher is replaced with an MML 7 with two tons of ammunition and an ER small laser. These modifications change it from a headhunter to a ranged support 'Mech.[1] BV (2.0) = 1,485[18]

Custom Variants[edit]

  • EXT-4DX Exterminator Caine 
    The personal 'Mech of Lieutenant Caine Barclay of the SLDF, this Exterminator removed the Null-Signature and Chameleon Light Polarization Shield as well as stripping out all of its weapons. In their place this version carried MASC and a supercharger, while each arm carried three medium pulse lasers. Each laser was equipped with a laser insulator to help diffuse the heat. The anti-missile system was retained, but a smaller engine dropped the cruising speed to 58 km/h. Despite the smaller engine, the MASC and supercharger allowed Barclay's 'Mech to reach burst speeds of 130 km/h. Though Barclay was successful in defeating ten DCMS MechWarriors in duels, the eleventh one destroyed his 'Mech.[22] BV (2.0) = 1,794[23]

Design Quirks[edit]

The Exterminator has the following Design Quirk:[24]

The EXT-4DX Exterminator Caine variant has following Design Quirks:[22]

The EXT-6CS Exterminator variant is subject to the following Design Quirks:[19]

Notable Pilots[edit]

See Category:Notable Exterminator Pilots



  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 Technical Readout: Succession Wars, pp. 120–121: "EXT-4D Exterminator"
  2. MUL online date for the Exterminator
  3. Combat Operations, p. 106
  4. Technical Readout: 3050 Upgrade, p. 209
  5. Technical Readout: 3039, p. 238
  6. Technical Readout: 3050 Upgrade, p. 209
  7. Technical Readout: 3025 Revised, Exterminator profile
  8. Technical Readout: 3050 Upgrade, p. 208: "Produced Exterminator Components on Caph"
  9. Technical Readout: 2750, pp. 38–39
  10. Technical Readout: 3025 Revised, pp. 83–84
  11. Record Sheets: 3039, p. 150
  12. Record Sheets: 3050 Upgrade Unabridged (Clan & Star League)
  13. Record Sheets: Operation Klondike, p. 44
  14. Historical: Operation Klondike, p. 160
  15. Technical Readout: Golden Century, p. 62
  16. Technical Readout: Golden Century, p. 105
  17. Combat Operations, p. 123
  18. 18.0 18.1 Master Unit List: Battle Values
  19. 19.0 19.1 Experimental Technical Readout: ComStar, p. 6
  20. MUL online BV for the EXT-6CSExterminator
  21. Recognition Guide: ilClan, vol. 14, p. 18
  22. 22.0 22.1 Experimental Technical Readout: Gunslingers, p. 6
  23. Experimental Technical Readout: Gunslingers, p. 19
  24. BattleMech Manual, p. 91: BattleMech Quirk Table -Exterminator Entry