|Manufacturer||Arcadia BattleMech Plant CM-T15
|'Mech type||Clan OmniMech|
|Chassis||Process 12 Endo Steel|
|Armor||Arcadia Compound Delta VII ferro-fibrous|
|Engine||Consolidated 315 XL|
|Communications System||KP-3 "Screamer"|
|Targeting Tracking System||Version Gamma-V TTS|
|Heat Sinks||12 Double heat sinks|
|Jump Jets||Clan Standard 14X Series Standard|
The Mongrel received its baptism of fire during the Battle of Tukayyid. There, it was commonly seen leading light Stars, especially on deep reconnaissance and raiding missions. Its ammo-efficient weapons allowed it to range far afield and helped simplify resupply, while its speed allowed it to dictate its range of engagement and outmaneuver all but the fastest of opponents. The 'Mech entered full production after a slight physical remodel the following year and was rechristened the Grendel after the code name given to it by Com Guard troops who faced it.
One of the few successes of Clan Diamond Shark's defeat on Tukayyid, the other Invading Clans almost immediately staged Trials of Possession for the renamed 'Mech. Rather than waste Warrior Caste resources in fighting the numerous Trials, the Diamond Sharks instead chose to sell production runs or license the design to the other Clans, speeding their recovery and ensuring the Grendel was a common sight among many front-line Clusters.
Though the Grendel remains in use among the other Inner Sphere Clans following the Wars of Reaving, most notably the Clan Hell's Horses, the majority of production during the Dark Age era resides in the Khanates of Clan Sea Fox.
Weapons and Equipment
The Grendel features a powerful 315-rated engine, enabling it to move at a fleet 119 km/h, and enough jump jets fixed on the chassis to propel it up to 210 meters at a leap. The Sharks spared no expense in weight-saving materials, making use of an XL engine, Endo Steel structure, and seven and a half tons of ferro-fibrous armor. The incredible speed of the Grendel is not terribly helpful in most zellbrigen duels, but it is effective in large-scale actions especially against Inner Sphere foes of similar weight hard pressed to counter its speed or firepower. The Grendel is also popular with technicians. While many OmniMechs are often "hangar queens," the Grendel can go long periods without maintenance and still remain combat effective.
The primary configuration uses an ER Large Laser at long range, but really excels at closer ranges. It mounts three ER Medium Lasers that can be devastating to light 'Mechs and a Streak SRM-6 that exploits any holes the lasers make. An ER Small Laser that is effective at point-blank range seems an afterthought. This design is best using its large laser to soften up an opponent, then dash closer in a flurry of lasers and missiles. Two extra double heat sinks help to keep the design mostly cool.
- Alternate Configuration D
- A different take on the primary configuration, the Grendel D mounts an ER PPC for long-range engagements. When the 'Mech closes, it brings a Medium Pulse Laser, ER Medium Laser, and SRM 6 to bear. A Small Pulse Laser provides protection against conventional infantry. BV (1.0) = 1,991, BV (2.0) = 2,212
- Alternate Configuration G
- The G is a scout version intended to strike fast at point-blank range, carrying twin Medium Pulse Lasers and Micro Pulse Lasers in its right arm supported by a single Medium and Micro Pulse laser in each side torso rounded out by a final Micro Pulse Laser in the head. A Supercharger allows the Grendel G to rapidly close with its foes while a Watchdog CEWS both protects and enhances its reconnaissance abilities. BV (2.0) = 2,209 
- Alternate Configuration H
- The H is configured to take advantage of heavy lasers. Bearing a close resemblance to the prime, the Grendel H uses a Heavy Large Laser, Streak SRM-4, two ER Medium Lasers, and a single ER Small Laser. Four additional double heat sinks strain to keep heat levels under control. BV (1.0) = 1,871, BV (2.0) = 1,965
- Alternate Configuration I
- Carrying a mixture of both Inner Sphere and Clan OmniPods, the Grendel I mounts a ProtoMech AC/4 along with ton of reloads in its right arm in support of a right torso-mounted plasma rifle with a single ton ammo bay, supported by a single ER Medium Laser in the left torso. BV (2.0) = 1,675  
- Alternate Configuration J
- The J configuration is a Streak Boat, mounting a Streak SRM-6 in its right arm and each side torso, drawing from a combined two tons of missiles. For support weaponry the Grendel J mounts a Small Pulse Laser in its head and pair of Improved Heavy Small Lasers in its left arm. BV (2.0) = 1,811  
- Alternate Configuration T
- The T configuration visually resembles the Prime but is a more short-ranged combatant, mounting a Large Pulse Laser and an Improved Heavy Small Laser in its right arm, supported by a right torso-mounted SRM-6 rack, head-mounted ER Small Laser, and twin Improved Heavy Medium Lasers in its left arm. A single ton of SRM reloads and extra Double Heat Sink fill out the weight. BV (2.0) = 1,936  
Original Grendel from The Black Thorns
Grendel from TRO:3058
Grendel from RG:ilClan v2
Grendel Prime in motion from CCG
- Technical Readout: 3058 Upgrade, pp. 168-169, "Grendel Profile"
- Record Sheets: 3058 Upgrades, p. 194
- Record Sheets: 3058 Unabridged (Clan & Star League), p. 126
- The Black Thorns, pp. 54-55
- Technical Readout: 3058, pp. 164-165, "Grendel"
- Recognition Guide: ilClan, vol. 2, p12 "Grendel"
- Record Sheets: 3058 Upgrades, p. 195
- Record Sheets: 3058 Unabridged (Clan & Star League), p. 127
- Record Sheets: 3058 Upgrades, p. 196
- Record Sheets: 3058 Unabridged (Clan & Star League), p. 128
- Record Sheets: 3058 Upgrades, p. 197
- Record Sheets: 3058 Unabridged (Clan & Star League), p. 129
- Record Sheets: 3058 Upgrades, p. 198
- Record Sheets: 3058 Unabridged (Clan & Star League), p. 130
- Record Sheets: 3058 Upgrades, p. 199
- Record Sheets: Upgrades, p. 73
- Record Sheets: 3058 Unabridged (Clan & Star League), p. 131
- Record Sheets: 3058 Unabridged (Clan & Star League), p. 132
- Recognition Guide: ilClan, vol. 2, p18 "Grendel F"
- Recognition Guide: ilClan, vol. 2, p19 "Grendel G"
- Record Sheets: 3058 Upgrades, p. 200
- Record Sheets: Upgrades, p. 74
- Record Sheets: 3058 Unabridged (Clan & Star League), p. 133
- Recognition Guide: ilClan, vol. 2, p20 "Grendel I"
- Recognition Guide: ilClan, vol. 2, p21 "Grendel J"
- Recognition Guide: ilClan, vol. 2, p22 "Grendel M"
- Recognition Guide: ilClan, vol. 2, p23 "Grendel M"
- BattleMech Manual, p. 92 BattleMech Quirk Table - Grendel Entry.