Pyukumuku is a marine Pokémon with an ovoid, black body. Its face has two beady, pink eyes and a white mouth shaped roughly like a star or Daimonji. This Pokémon is capable of spitting its organs out through its mouth. The white organs can take different shapes, such as a fist. Two lines of three pink spikes run down each side of its back. The middle spike of each line is about twice as long as the others are. A fluffy white puff forms its tail.

Pyukumuku tends to find a spot it likes and stay there, even returning to the same spot if moved. Once all the food in its favorite spot has been consumed, it will continue to stay there to the point of starvation. Its body is coated with a viscous fluid that allows it to stay on land for a week without drying out. This fluid is also beneficial to people as a moisturizer. If stepped on, it will expel its fist-like organs and smack the perpetrator. It particularly hates having its mouth or spikes touched. Tourists dislike Pyukumuku due to its appearance and lifestyle and often accidentally step on Pyukumuku. This creates a need for part-time jobs on beaches chucking this Pokémon back into the sea. However, people in Alola have already taken to throwing the Pokémon back to the sea where it can find food when thin. Pyukumuku is shown to have a symbiotic relationship with Pelipper, which carries it after scooping it from the water.

(Source: Bulbapedia)