Mole rat (Fallout 76)
The mutated African mole rat is a creature with a complex history, developed for a covert U.S. bioweapon research project: Mission Cloacina. In order to undermine Chinese infrastructure, the naked mole rat would be tailored into a biological weapon, the Mutant Undermining Lifeform. When released into enemy territory, its aggressive qualities, hunger, and breeding rates would enable it to undermine local infrastructure. The MUL genetic design used rodent stock primarily, ranging from the common sewer rat, through the naked mole rat, to the African mole rat. A genetic kill switch was coded into their DNA, allowing the military to purge the MUL from an area in short order, only having to clean them up. The project's effectiveness against China is unknown. What's known is that the MULs escaped into the wild during the Great War, becoming a common pest across the United States.
Although the MUL is genetically closest to the African mole rat of family Bathyergidae, its appearance closely resembles that of the naked mole rat, Heterocephalus glaber, enlarged due to exposure to radiation. It is significantly larger than its predecessors, but an increase in body mass and strength was not accompanied by a corresponding increase in brain mass (its brain organ is disproportionately small). Its incisors are razor sharp thanks to increased enamel and dentine growth, while low levels of substance P (a neuropeptide tied to pain and inflammatory processes) provide it with a phenomenally high pain tolerance. MULs are very adept burrowers, easily traveling underground and bursting through the surface to ambush their prey.
Mole rats tend to travel in dens of 3-5 and attack by lunging with their chisel-like teeth. They have a habit of ambushing the player by bursting through the topsoil and attacking unprovoked. At later levels, they are not particularly dangerous, but early in the game, a pack of mole rats can turn out to be a reasonably difficult fight, especially since they retreat into the ground after taking damage, and pop up behind the player character to attack again.
- Citadel terminals; Pentagon Library Terminal, Mission Cloacina Report: "CODENAME: CLOACINA
Development of the Mutant Undermining Lifeform continues apace, and our chief bio-engineers are certain that they will be able to perfect these living weapons in time for deployment into Red China.
Once covertly released into an enemy's environment, their aggressive qualities, dangerous hunger, and pervasive breeding should severely undermine the infrastructure of the location in short order, softening the target for ground invasion. At this point, the genetic kill-switch can be activated, allowing for easy reclamation -- not including a significant, one-time clean up effort.
Current MUL development primarily uses genetic stock of rodents, particularly the common sewer rat, and progress has been significant. FEV testing has been rejected, however, as the results are sterile."
- Enclave field terminals; Enclave Field Research Terminal, Field Entry: Molerat: "Kingdom: Animalia
Subject most closely resembles a Heterocephalus Glaber with enlargement due to heavy radiation. While much larger in size than generational ancestors, the local variety seems to have similarly low brain function, possibly due to an exceedingly tiny brain organ. Subject's incisors show increased enamel and dentine growth, making them razor sharp. Further study reveals extremely low levels of Substance P giving this subject an incredible tolerance to pain. I will take skin samples of my next subject as I believe the lack of Substance P can be spliced and manipulated for beneficial research, but this theory requires testing in a more fitting lab."
- Fallout 4 loading screen hints: "Mole Rats often travel underground and then burst through the surface to ambush their prey."