m Muk is also found in Unova in Pokémon Black and White 2. They can be found in the Castelia Sewers via rippling water and fishing during the spring and summer and Route 9 in the tall grass.
Muk look very similar to its previous form, Grimer. The main differences are that Muk is larger than Grimer, and has a wider mouth and smaller eyes. It is also usually shown with its left arm being much larger than the right one, along with a strand connecting its upper and lower lip when its mouth is open. The sludge it is made of is apparently less dense than water as it has been shown to float on it in the anime.
Gender differences
None.
Special abilities
The toxicity of Muk's form has reached the point where a single drop of it can make an entire lake stagnant and rancid. Its footprints are toxic enough for a person to contract influenza if they are touched. Their infamous stench increases in the summertime, due to the toxic substances in its body intensifying. Their ability to exist in the environment without it becoming completely hazardous to other lifeforms may be attributed to their ability to actively control their toxins, as they would likely never want to deliberately pollute a river or spread any harmful diseases.
This Pokémon likes warm and moist places. Groups of them accumulate in dirty places, such as garbage dumps or sewers. They sometimes also reside in dirty back alleys of towns. Despite their penchant for thriving in dirty, contaminated places, they do seem to have a limit as to how much pollution they can tolerate, as no Muk lived in the Lake Lucid of fifty years ago until some work was made on purifying it. Wild Muk are normally found only in Kanto and Unova.
From Muk's body seeps a foul fluid that gives off a nose-bendingly horrible stench. Just one drop of this Pokémon's body fluid can turn a pool stagnant and rancid.
This Pokémon's favorite food is anything that is repugnantly filthy. In dirty towns where people think nothing of throwing away litter on the streets, Muk are certain to gather.
Although Muk's body is very poisonous, it doesn't seem to harm Ash and the others when Muk is 'hugging' them. This is probably because it is able to control whether it gives off poison or not similar to how Ponyta can choose whether or not to burn the person that touches it. Croagunk is another Pokémon which is able to control the amount of poison it uses via its fingertips when using Poison Jab, or Sharpedo activating its Ability, Rough Skin.
Muk is tied with Mew for the shortest English name out of all Pokémon.
Muk shares similar traits to Weezing and Garbodor. All three Pokémon are pure Poison types with a single pre-evolution, roughly the same base stat totals and evolution levels, and appear to be based of a certain pollution; Muk being water pollution.
Origin
It appears to be a pile of living sludge. Muk may also be based on the imagined fear that heavy pollution, caused by the leakage and/or improper disposal of toxic/radioactive waste, may result in the creation of new and undesirable life.
Name origin
Muk is a corruption of muck (generally something filthy).
Betbeton may be derived from べとべと betobeto (sticky).
This Pokémon article is part of Project Pokédex, a Bulbapedia project that aims to write comprehensive articles on each Pokémon species, as well as Pokémon groups and forms.