It is capable of disguising itself as anything it likes. Although it appears to be a bird Pokémon, this is just an illusion. No one has seen its true form.
Masking is a Pokémon that is able to disguise itself as anything it likes. Its default form is a small black-and-white bird Pokémon, where one half of its face is white and the other half is black. It has a feather on the top of its head with an eyespot on it. It has white ruffles around its neck and white wings. It has two tails, one black and one white, each with an eyespot. Its underbelly is blue and it has two small stubby legs.
However, because Masking is the Illusion Pokémon, there is some dispute over whether this is its true form or not. It may also appear as any other Pokémon it chooses, although it is limited to Pokémon of the same size.
Masking is a powerful Psychic-type even at early levels. Its illusion powers are highly developed, allowing it to conceal itself and trick opponents.
Masking is so elusive and shy that there is even some debate as to whether it really exists. It disguises itself as another Pokémon and flees when it sees humans. However, sometimes they like to play tricks on others.
Masking live among humans in cities, often disguising themselves as other small Pokémon. This disguise is so complete that Rosalind is one of the only trainers known to have caught one; due to her training in theater she is able to spot the chinks in its disguise.