Munna is a pink, nearly spherical, quadrupedal Pokémon of indefinable basis. It has four tiny tapered limbs and a tapered snout that largely obscures its sizable mouth. Munna has shiny, oval, red eyes with two discernible upper eyelashes. Between its eyes is an oval spot in a darker shade of pink, from which Munna can expel Dream Mist. Purple, five-petal flower markings with dark pink centers ornament much of its body. It is able to constantly float in the air.
Munna is able to eat the dreams of people and Pokémon, as well as project these dreams by expelling Dream Mist. A person whose dream was eaten by a Munna will forget the dream's contents. The Dream Mist will be pink if the dream was pleasant. However, Munna can also seek out and cure people and Pokémon who are having nightmares. Munna and its evolution are thought to share common ancestry with the Drowzee line according to one of Drowzee's Pokédex entries.
Munna is featured in the first promotional C-Gear skin. It is available by default in Japan but required a password internationally.
Munna and Musharna were designed by Atsuko Nishida. Munna was designed after Musharna, which itself was designed before the concept of the Dream World was created.