Fanon Pokedex / Grimer

Grimer Line

Morphs [Oak Catalog #]

  • Grimer [088]
  • Muk [089]

Physical Description: Grimer and Muk

Grimer and Muk look like mobile piles or puddles of sludge. This sludge is usually purple, although brown, black, gray, and green Grimer and Muk have been recorded. Grimer and Muk also have two gray spots near the center of the Grimer/Muk. These are commonly misinterpreted by artists to be fully functional eyes. Grimer are about 1-3 feet in height and 4-12 feet wide. Muk are about 6 feet tall and 15 feet wide, but are usually larger. Muk usually are wider than Grimer, but the surefire way to tell the difference is the stench.

Notable Biology: Grimer

Although Grimer appears to be a single organism, it is actually a colony of simple pseudoorganisms. The cellular structure is radically different than that of other organisms, appearing to be constructed of petroleum compounds and other industrial waste products. They also emit X-ray radiation, which has led some to believe that is it sludge exposed to X-rays. These pseudoorganisms have a weak form of specialization, forming rudimentary eyespots and an extremely simple digestive sac. Most types of this pseudoorganism die off upon contact with the air, rapidly decaying into an extremely toxic and putrid smelling byproduct that Grimer uses as a natural defense mechanism. This byproduct can be reconverted into cells, resulting in only a mild net loss of Grimer. The organisms making up Grimer are highly acidic, and decay rapidly and spectacularly when a base is applied. Therefore, soaps and cleaning supplies are an effective way of dealing with Grimer, although this has the side-effect of making the Grimer explode.


When three to four Grimer have been combined, or a Grimer gets large enough from consuming sludge, the cells of the entire organism mutate or "evolve", transforming the Grimer into a Muk.

Notable Biology: Muk

Muk, like Grimer, are also colonies of simple pseudoorganisms. Differences at the microscopic level between Grimer and Muk are very little, but they create an overall different creature. For starters, the cells of a Muk decay much more vigorously. This causes the secretions of the Muk to have much different properties; it emits an extremely foul-smelling odor, it slowly causes anything it comes in contact with to decay, and it is about 30 times as poisonous. The secretions also create a film around the Muk, making it more durable. However, the secretions are not able to be reconverted. This means that the Muk needs to consume much greater amounts of food than a Grimer would. Fortunately for the Muk, the Muk is more suited to mass consumption. Muk are only limited in size by the amount of food in the area.

Habitat: Grimer and Muk

Anywhere there is sufficient oil, sludge, or pollutants. Common locations include industrial plants, sewers, and polluted bodies of water.

Diet: Grimer/Muk

Grimer and Muk consume raw sewage, toxic chemicals, nuclear waste and other hazardous substances. They have been known to congregate in sewers or dirty industrial plants to feast on the sludge in these areas, to the point of clogging the sewers or shutting down the power stations. Although the problem is frequently dealt with by driving the Grimer and Muk away, some enterprising cities and factory owners have actually begun taming the Grimer and Muk to raise in captivity. They will feed the Grimer and Muk the toxic byproducts of their operations, effectively using the Pokemon as living waste disposal systems. This has proven a highly effective solution both in dealing with toxic pollutants and in avoiding the problems caused by large numbers of these Pokemon gathering in particular places.


Grimer and Muk colonies secrete an acidic, virulent, and extremely toxic chemical. This comes from the decay of the organism upon coming into contact with air. Secretions from a Muk are more virulent than those from a Grimer, and cause anything it comes in contact with to decay. Contact with Grimer secretions causes death in plants and small Pokemon, and poisoning in trees, larger Pokemon and humans. Symptoms of Grimer poisoning include a fever, nausea, and a rash where the secretions came into contact. Muk secretions cause plants, trees, and small animals to die, and potentially fatal poisoning in humans and larger Pokemon. Symptoms include shortness of breath, blurred vision, shock, and paralysis.Grimer are also capable of physically attacking, usually by attempting to suffocate the target. Larger Muk are capable of grabbing individuals and consuming them whole. Muk are also able to fling their sludge for long distances. Grimer and Muk are also radioactive, emitting potentially harmful X-rays.

Curiously enough, however, the harmful effects of contact with a Grimer or Muk only appear to take place when the Pokemon actually wills it. Grimers and Muks used in Pokemon battles typically only apply enough toxicity to harm their opponents, but no more so than the typical attacks of an Electric or Fire-type Pokemon. In fact, contact with a Grimer or Muk may be completely harmless. The world-renowned Pokemon biologist Professor Samuel Oak frequently entertains fellow Pokemon researchers as guests at his laboratory just outside Pallet Town, Kanto. Many of these guests have reported being affectionately smothered by a Muk owned by one of the trainers that Professor Oak supports, and that is typically kept at the Professor's lab. No one who has been slimed by this Muk has ever suffered any medical problems from it, and their doctors have uniformly assured them of their good health.


Grimer and Muk do not court. Muk, if the individual is large enough, bud, producing Grimer. Muk also, if there is a lack of food, split into anywhere from three to twelve 'pseudo-Muk'. These eventually convert into Grimer over the course of an hour, enough for them to not attack each other right after mitosis.

Social Structure

Grimer and Muk are independent creatures. If two Grimer meet, they attack each other, eventually merging into a larger Grimer. If two Muk meet (which is both extremely rare and a sign of negligence and uncleanliness), they also attack each other, using surprisingly creative methods to turn the other Muk into a consumable sludge. Grimer keep a safe distance from Muk, and Muk eat Grimer as they do anything else.

Ways of Extermination:

Grimer occasionally appear in filthy houses and workplaces. If they do, the most effective way to get rid of them is to either clean up the area and remove the Grimer's food source, or to gather all the toxic material and feed it to the Grimer, after which it will move on if it can no longer find any "food". Other options are to call a professional Pokemon exterminator to capture and then release the Pokemon, or even to sell the Pokemon to a public works department or a heavy industrial company, both of whom have increasingly begun using these Pokemon as living garbage disposals, as mentioned above.

Using fire is not recommended, as while it destroys the Grimer, it creates toxic vapor and the Grimer survives for about fifteen seconds after ignition.

Other Notes

Despite their general acidity, Grimer and Muk can be caught and stored in Pokeballs in much the same way as any other Pokemon. Trainers should note that the disgusting stink emanated by many Grimer and Muk will emanate through the Pokeball, and they should be prepared to deal with the reactions other people and Pokemon may have to the smell. In some cases this may in fact be beneficial, as several trainers have reported that the stink emanated by their Grimer or Muk actually serves to repel wild Pokemon that would otherwise have attacked them.

Written by Thnikkafan.