It is not known to evolve into or from any other Pokémon, but it is considered to be a counterpart of Passimian.
Oranguru is a large, white Pokémon resembling an orangutan. While most of its body is covered in white fur, its hands, feet, and snout are bare with its light gray skin visible. The fur around its head and under its chin is longer, and creates the impression of a long beard. It has a broad, flat nose and a black area around its eyes, which has light blue markings underneath, yellow sclerae, and white irises. In the center of its forehead is a yellow marking shaped like a four-pointed star. A cape of purple fur covers its back and is divided into many wavy clumps. There are a few strands of orange or light blue hairs in the clumps near the front. Oranguru holds a fan created from green leaves woven together with its own purple fur.
This solitary Pokémon spends its time deep in the forest, meditating high up in the trees. While it is not normally active, it will provide food to hungry Pokémon and give medicine to injured ones. It has even been known to use human tools or items, including Poké Balls. This can make them difficult Pokémon for Trainers to handle. Ancient people actually thought Oranguru were people, and called them the "people of the forests." Oranguru does not get along with others of its kind, often battling out their wits for superiority.
Oranguru debuted in Mallow and the Forest Teacher!, where it helped Mallow after she was injured while running away from home. Oranguru ran a small bar in the forest and was revealed to have helped Mallow's father Abe when he was younger.
Oranguru can be seen as a counterpart to Passimian. Both are primate-like Pokémon with the same base stat total. While Oranguru is exclusive to Pokémon Moon and Pokémon Ultra Moon, Passimian is exclusive to Pokémon Sun and Pokémon Ultra Sun.
Oranguru is based on an orangutan and a guru. The name "orangutan" translates as "person of the forest", which Oranguru is also referred to as. It may also be based on the mythical satori, an ape-like yōkai which could read human minds.
Oranguru may be a combination of orangutan and guru.
Yareyuutan may be a combination of やれ yare ("do it") and オランウータン oran'ūtan (orangutan).