Production information
Manufacturer Earthwerks Incorporated

Toddlette Industries[1]

Production Year 2475[2][3][4]
Model FLE-17[5]
Class Light
Cost 1,728,000 C-bills
Technical specifications
'Mech type Inner Sphere BattleMech
Mass 20 tons
Chassis Earthwerk Trooper II endo steel[5]
Armor Livingston Ceramics[5]
Engine GM 120[5]
Communications System Neil 2000[5]
Targeting Tracking System Dalban HiRez-B[5]
Heat Sinks 10 single heat sinks[5]
Speed 97[5] km/h (119[5] km/h with MASC)
BV (1.0) 371[6]
BV (2.0) 510[5][7]


Focused on speed and firepower, the lightly armored Flea was an extremely rare sight until the arrival of the Wolf's Dragoons mercenary unit, with the design experiencing a revival as an inexpensive recon and anti-personnel militia 'Mech.[8][9]

Initially called the Trooper when it was introduced as the Free Worlds League's first light scout BattleMech in 2475, the design was so heavily flawed that it took 25 years before all the issues were corrected, with a new name selected to escape the bad press.[10] The early prototype was designed by Colonel J. Marcus Llewelyn-Jaymes and his handpicked team at Toddlette Industries in a bid to create a dedicated reconnaissance BattleMech for the Free Worlds League Military. The design was considered highly maneuverable and lightweight at the time, and utilized a basic chassis similar to their larger WorkMechs; the 'Mech's systems appeared straightforward, with a power plant, gyroscope, cockpit, and other critical systems housed in an "armored-box" mounted on reinforced, armored "bird-walker" legs. Only with the help of Col. Llewelyn-Jaymes contacts in the military and government circles, and according to rumors, possible bribery of politicians and decision makers, the FWLM ultimately accepted delivery of the Trooper. While it was considered easy to maintain by technicians and logisticians, it wasn't long before it gained a poor reputation among those that piloted it. Since the design was based off their WorkMechs, it completely lacked any dedicated ejection mechanism, and forced pilots to manually exit should they become disabled. Additionally, the legs proved to be unable to cope with heavy combat, which became apparent in various failed trials before the FWLM's Minister of Defense. Despite these shortcomings, the League's Chief Armorer and Quartermaster General continued purchasing the prototype year after year. This ultimately led to the Trooper being selected as the very first FWLM 'Mech to be upgraded with "modern" technology in 2501 and rechristened as the FLE-4 Flea.[11]

While produced on and off until the early Succession Wars, excessive losses of the lightly armored design led Earthwerks to switch its production line to manufacturing heavier designs. This changed with the arrival of Wolf's Dragoons, who brought with them a large number of Fleas and reached an exclusive production arrangement with Earthwerks that resulted in the company opening new lines to replenish the Dragoons' losses in the Fourth Succession War.[10] With multiple lines on Asuncion, Bernardo and Victoria, after letting the Dragoons' exclusivity clause lapse, Earthwerks started selling the easy to manufacture, easy to maintain 'Mech by the DropShip load across the Inner Sphere.[5]

Originally produced exclusively for the Dragoons until the Capellan Confederation acquired the design's blueprints via a Maskirovka raid during the 3040s, the post–Helm Memory Core FLE-17 variant is based on the older FLE-15 model. Since the Dragoons used the Flea in a recon role more than an antipersonnel 'Mech, Earthwerks conceived a new design by incorporating recovered technology. Retaining the design's maximum speed of 97.2 km/h, the addition of an endo steel chassis frees up weight for a MASC system that allows the 'Mech's speed to be pushed up to 129.6 km/h in short bursts. The increase of speed is required to ensure survival on the modern battlefield, as the FLE-17 is only clad in a pitiful three tons of Livingston Ceramics armor plating.[5][9]

Once the FLE-17 plans were captured and the Dragoons' contract clause lapsed, Earthwerks began producing the new design almost exclusively for the Confederation until 3053, which saw use within their numerous militias. It was rarely seen among any of the other Great Houses' military, but some sightings did appear after on the mercenary markets with Dragoon serial numbers, which gave some credibility to reports of Wannamaker's Widowmakers operating an extensive salvage operation on Outreach. With the Confederation's later advances in stealth technology and light weaponry, the Flea became a logical test platform for new prototypes. These performed well, which encouraged Earthwerks to refit several older models.[5]

Weapons and Equipment[edit]

The FLE-17's primary weapons are two Martell medium pulse lasers, replacing the FLE-15's more mundane standard lasers. These are backed up by an Olympian flamer which works well for anti-personnel use. The Flea also has two rear-mounted Martell small lasers for point defense.[5][9]


  • TP-1R 
    The predecessor to the original Flea FLE-4 model, the Trooper TP-1R prototype was built in 2475, by Toddlette Industries, on a primitive chassis and maintained ground speeds of nearly 100 km/h. Its weaponry was mounted in fully articulated turret-style pods, and only consisted of two small lasers in the left arm, a machine gun in the right fed by only half a ton of ammo, and a chin-mounted flamer. It was protected by only two tons of primitive armor.[11] BV (2.0) = 236[12]
  • FLE-4 
    An original Flea model, the FLE-4 is built on a standard chassis and has a maximum speed of 97.2 km/h. The 'Mech was armed with a Martell large laser, allowing it to attempt to keep any heavier 'Mechs at a stand-off range if they attempt to engage, and is supported by two Martell small lasers for close in work as well as an Olympian flamer for anti-infantry purposes. The cost of its relatively heavy weaponry and high speed is its two tons of armor, half that of even the venerable Locust and the reason why the 'Mech was discontinued.[13] BV (1.0) = 360;[6] BV (2.0) = 427[10]
  • FLE-14 
    Entering production in 2519 the FLE-14 Flea was an attempt to create an ultralight BattleMech. Weighing a mere 15 tons, it could arguably be regarded as a different 'Mech design. It was capable of a maximum ground speed of nearly 150 km/h, with an average cruising speed near 90 km/h, and this variant also had a 120 meter jump capability. Its weapons and armor however were very light: Only one ton of armor protected the unit, and the single medium laser mounted in the right arm was barely enough to make it a viable battlefield unit. Intended to replace the Wasp or Stinger scout 'Mechs, the FLE-14 was definitely quicker, but the low armor protection and limited jump range made it vulnerable. As a result, it saw only one production run and was phased out once its shortcomings were revealed.[14] BV (2.0) = 270[15]
  • FLE-16 
    Built as part of Wolf's Dragoons' exclusive contract with Earthwerks Incorporated to replenish the Dragoons' losses at the end of the Fourth Succession War, alongside renewed production of original Fleas, the FLE-16 was the first new production model of the extremely rare 'Mech in centuries. The variant remedied the earlier FLE-14's weaknesses by combining incredible speed with additional armor and weaponry on a 20 ton chassis; the engine was upgraded to a GM 180 in order to reach a similar maximum ground speed of 151 km/h, and it mounts two Martell medium lasers supported by an Olympian flamer while retaining an armor profile like the earlier FLE-15. Even though the FLE-16 carries more weaponry than its ultralight predecessor, the armor is still too low to endure direct combat.[13] BV (2.0) = 506[13][17]
  • FLE-21 
    Another Capellan variant, the FLE-21 mounts a 180-rated Light engine supplemented by a supercharger, giving it a top speed of more then 140 km/h. While still having very little armor, it is also protected by a Guardian ECM Suite. Like its cousin, the FLE-20, the model 21 mounts stealth armor, and also shares the pair of ER Medium Laser, along with an ER Flamer for work against infantry units. Wolf's Dragoons placed a large order for the 21 model, trying to see if they could also be used as a light 'Mech hunter. BV (2.0) = 823 [20]
  • "Fire Ant" 
    A vicious anti-infantry variant, the origin of the Flea "Fire Ant" is a mystery, with Earthwerks denying the design.[5] It was first seen in the Chaos March, most notably in urban fighting on Carver V, in 3063[21] and none were spotted after 3068.[5] Possibly the predecessor to the FLE-19 and -20, the exact configuration is not known, if one even exists, as it seems to be a refit variant of sorts.[5] The typical Fire Ant refit removed half a ton of armor in favor of six machine guns and three flamers.[22] It was thought to be a designated pacification unit, in the sense of a SecurityMech, as opposed to a frontline BattleMech design.[5] BV (2.0) = 332[22][23]

Apocryphal Variants[edit]

Apocryphal Content Starts

The information after this notice comes from apocryphal sources; the canonicity of such information is uncertain.
Please view the reference page for information regarding their canonicity.

These variants were introduced in various apocryphal sources, and thus far have not appeared in any canonical media.

From MechWarrior Online:

Apocryphal Content Ends

Design Quirks[edit]

The Flea and variants, unless specified otherwise, are subject to the following Design Quirks:[25]

The FLE-14 Flea variant is subject to the following Design Quirks:[14]

The TP-1R Trooper variant is subject to the following Design Quirks:[11]

Notable Pilots[edit]

See: Category:Notable Flea Pilots


  • The FLE-4 and FLE-15 originally appeared in Stardate magazine,[26] which is no longer considered canonical. Even then the Flea's original Trooper name was mentioned as part of its history.
  • The Fire Ant variant is derived from the 'Mech of the same name found in the video game MechCommander 2. Although the 'Mech in the game is never referred to as a Flea, the in-game art, the specifics, and the reference to the design in Technical Readout: 3050 Upgrade and the stats for it in Record Sheets: 3050 Upgrade (Inner Sphere) establish that the Fire Ant is a Flea variant. The Fire Ant will also make its second video game appearance in MechWarrior Online with an apocryphal designation: FLE-FA.[27]
  • Wolf's Dragoons arrived in the Inner Sphere with a half-dozen of the otherwise rare (at the time) Flea BattleMech. They were down to only a pair at the end of the Fourth Succession War and ordered many more when a deal was reached with Earthwerks.[10]
  • The Flea was the sixteenth BattleMech announced for MechWarrior Online, but it would not be added to the game for a long time; the developers had indicated it may never be developed, to the point of hiding and obscuring the announcement page for the 'Mech. The Flea finally resurfaced for preorder on March 1st 2018, more than five years after its original reveal.
  • In German products, the unit's proper name was translated to Floh. The model code was accordingly changed to FLO-4.



  1. Experimental Technical Readout: Primitives, Volume 5, p. 3, "Produced Trooper and Flea 'Mech"
  2. Era Digest: Age of War, p. 11
  3. Wolf's Dragoons, p. 105: "...the Trooper name was abandoned in favor of the more descriptive Flea."
  4. Technical Readout: 3039, p. 242: "...the FWL renamed [the Trooper] the Flea."
  5. 5.00 5.01 5.02 5.03 5.04 5.05 5.06 5.07 5.08 5.09 5.10 5.11 5.12 5.13 5.14 5.15 5.16 5.17 5.18 5.19 Technical Readout: 3050 Upgrade, p. 8: "FLE-17 Flea 'Mech Profile"
  6. 6.0 6.1 6.2 Combat Operations, p. 130
  7. Record Sheets: 3050 Upgrades Unabridged (Inner Sphere), p. 6
  8. Technical Readout: 3050, p. 50: "Flea Profile"
  9. 9.0 9.1 9.2 Technical Readout: 3050 Revised, pp. 46–47: "Flea 'Mech Profile"
  10. 10.0 10.1 10.2 10.3 10.4 Technical Readout: 3039, p. 242: "FLE-4 Flea Profile"
  11. 11.0 11.1 11.2 Experimental Technical Readout: Primitives, Volume 5, p. 3
  12. MUL Profile for TP-1R includes BV2.
  13. 13.0 13.1 13.2 13.3 Technical Readout: Succession Wars, pp. 6–7: "FLE-16 Flea"
  14. 14.0 14.1 Experimental Technical Readout: Succession Wars, Volume 1, p. 3
  15. MUL Profile for FLE-14 includes BV2.
  16. MUL online entry for FLE-15
  17. Record Sheets: Succession Wars, p. 7
  18. Record Sheets: 3050 Upgrades Unabridged (Inner Sphere), p. 7
  19. Record Sheets: 3050 Upgrades Unabridged (Inner Sphere), p. 8
  20. Recognition Guide: ilClan, vol. 26, p. 12
  21. 3063 is the introduction date of the Fire Ant according to the Master Unit List
  22. 22.0 22.1 Record Sheets: 3050 Upgrades Unabridged (Inner Sphere), p. 9
  23. MechCommander 2, In-game encyclopedia
  24. MechWarrior Online "Flea Sale Page"
  25. BattleMech Manual, p. 91: Design Quirk Table - Flea Entry
  26. Stardate Vol. 3, No. 1, pp. 4–5
  27. FLE-FA designation introduced by MechWarrior Online; canonical sources otherwise only refer to it as the Flea "Fire Ant" variant