Muk is a term that refers to a type of slime or gooey substance often found in various environments, such as ponds or marshes. It can be composed of organic materials, bacteria, and algae, contributing to the ecosystem by providing nutrients and serving as a habitat for small organisms. In some contexts, "Muk" may also refer to a character in the popular video game series Pokémon. This character is a Poison-type Pokémon known for its sludge-like appearance and ability to absorb toxins, making it a unique addition to the game's diverse roster of creatures.