Cosmoem is a Pokémon in the shape of a translucent, dark-blue orb with a starscape pattern set in a golden shell-like structure. The main portion of the shell is a flat oval around the center of the orb. Eight more flat, half-oval projections surround the orb in an asterisk-shape. At the center of the main body is a much smaller black core. The upper half of the core has a thin blue line on the front, back, and each side, while the lower has pink lines. On the front are two orange semicircles, which appear to be closed eyes. The overall shape of this Pokémon also resembles an eye.
Encased in its sturdy, cocoon-like shell, Cosmoem is unable to move. In Pokémon Refresh, it cannot even eat. It grows as it absorbs starlight and the dust in the air. Its body is warm to the touch. Cosmoem's shell is said to be harder than any known material. In ancient times, it was worshipped as the "cocoon of the stars" by the people of Alola.
With its pre-evolved form weighing in at 0.1 kg (0.2 lbs.) and Cosmoem at 999.9 kg (2204.4 lbs.), the evolution from Cosmog to Cosmoem is the largest increase in weight due to evolution, with an increase of 999,800%.
Cosmoem and its pre-evolution are the only Pokémon who are unable to damage an opponent outside of Struggle.
In contrast, Cosmoem is also the heaviest Psychic-type Pokémon.
Cosmoem's evolution from Cosmog has the greatest standard deviation of all Pokémon, with 47.14, meaning that the changes to its base stats on evolving are the most uneven out of all Pokémon.
Cosmoem has the smallest movepool out of all evolved Pokémon, with only three moves that it can learn.
Origin
Cosmoem has characteristics of both a stylized sun and a stylized moon, having rays and a pair of crescents, respectively. Its enormous weight despite its extremely small size shares similarities with super-compressed astronomical bodies such as black holes and neutron stars. Given its description, it seems to be an embodiment of star formation in general. It may also be based on the idea of the world egg. When viewed from the front, its shape resembles an eye.
Name origin
Cosmoem may be a combination of cosmo, ovum (Latin for egg), and embryo.