Masquerain is a light blue Pokémon with two pairs of rhombus-shaped wings on each side of its body. Its head is shaped like an elongated teardrop with a pink face and round, black eyes. On either side of its head is a large, antenna that resembles an angry eye. The antennae are white with pink along the lower rim. White lines along the rim resemble eyelashes, while a large, dark pink dot in the middle represents the pupil or iris. These eyespots are used to intimidate enemies.
Masquerain's four wings allow it to fly in any direction and hover, but it cannot fly when its wings are wet. Additionally, rainy weather causes its antennae to become heavy and droop. In order to protect its wings and antennae, this Pokémon will shelter under trees or the eaves of houses. Masquerain lives on water's edge.
A Masquerain appeared in Destiny Deoxys, under the ownership of Audrey. It was her main Pokémon, and it helped to rotate the fan blades of the windmills in order for LaRousse City's power to come back on.
A Masquerain appeared in Dewpider Ascending!, where it resided near the Pokémon School. It evolved from Surskit during a battle against a Dewpider over its territory. The battle ended when Masquerain, pleased with its evolution, flew off and allowed Dewpider to live near the Pokémon School.
Masquerain can be seen as a counterpart to Araquanid. Both share the Bug type and the same base stat totals, and both can be found at Malie Garden in Pokémon Sun and Moon, taking the place of the other depending on the time, with Masquerain being found during the night and Araquanid in the day.
Furthermore, Masquerain and Araquanid share the same base stat total of 454. In fact, this reflects a 40-point boost across Masquerain's original base stat total of 414 between Generations VI and VII.
Masquerain is based on insects, especially moths, that bear eyespots to frighten would-be predators. Its head is shaped like a raindrop, making it similar to some lanternflies, and its flight is similar to that of a damselfly. It could have also been based on the Kalligrammatidae, ancient lacewings (damselfly-like insects) that resembled butterflies and moths.
Masquerain is a combination of masquerade (a disguise) and rain.
Amemoth is a combination of 雨 ame (rain) and moth.