Unown is a flat, thin Pokémon shaped like an eye with appendages that make it resemble a letter or a punctuation mark. It is entirely black, except for its white sclerae. All twenty-six alphabetic forms of Unown have fully open eyes while the two punctuation Unown have half-closed eyes. Though each of its forms has a counterpart in the Latin alphabet, Unown is said to resemble ancient writing and hieroglyphs. It is a mystery whether Unown predates or postdates written language, and therefore which one is based on the other.
The Pokédex and Professor Oak's research disagree on whether Unown communicates using electromagnetic waves or telepathy. Either way, it can be detected by the Pokégear radio, which interprets it as the melody of the Azure Flute. It is said that an "odd power" emerges when more than one Unown come together. In the anime, it is capable of reading the thoughts of other life forms. Great numbers of Unown are capable of distorting the reality to suit the dreams and wishes of whoever is in control of the Unown. However, they can only do this when more Unown are present, so it could be a shared effort rather than an ability unique to each Unown.
Unown is an extremely rare Pokémon that lives in its own dimension and rarely ventures outside. When it moves to the Pokémon world, Unown tends to stick to walls like engravings of ancient texts or orbit other Unown.
In PK21, an Unown F fell out of the Unown Dimension following an unspecified incident, and Pikachu and his friends had to help it return to the Unown Dimension so it could reunite with the other Unown.
Unown first appeared in Into the Unown at the Ruins of Alph. During a battle with Team Rocket, Gold has his Sunbo use Flash, accidentally awakening the Unown from their slumber. Angered, the Unown retaliated on the Team Rocket Elite Trio, defeating them. Bugsy later returns to study the Ruins further in Hurray for Heracross, where he captures an Unown G and gave to one of his colleagues. Later as he searches for Suicune he finds two chambers with Unown markings. Using his device to translate them, they read the following.
Three Unown appeared in a flashback in Raising Raichu, being the N, G, and U forms.
The English Pokédex data for Unown cards in the Neo Destiny expansion say that it is believed that the variety of types of Unown is a result of evolutionary adaptation, but this is not present in the original Japanese text.
When one Unown is released from a Poké Ball, it will fly off the screen. It then returns with a large swarm, similar to what Beedrill did in the original Super Smash Bros. The only difference is that Beedrill only attacks from left or right while Unown can come from any direction. Any opponent caught in this barrage is damaged and juggled.
There are also a number of Unown Poké Floats featured in the Poké Floats stage. In the second half of the stage's cycle, numerous Unown fly across the screen. Towards the end of the cycle, staying on the stage relies on hopping between the Unown.
These Psychic-type symbol Pokémon resemble ancient hieroglyphics found on rocks, a resemblance that's said to be more than superficial. Quite a few different shapes of Unown have been confirmed, and it's believed that each type has unique abilities. These enigmatic Pokémon can be found in the Ruins of Alph.
In Spell of the Unown: Entei, Professor Oak had some pictures of Unown on his computer which have never appeared in any other media. Some resemble Greek alphabet letters, particularly σ (lowercase sigma), Σ (capital sigma), Π (capital pi), and Ω (capital omega). The top left large image also resembles the Greek ligature, Ȣ (ou). Others resemble the Cyrillic letters ю (yu) and б (lowercase be). The Unown in the top-middle large image resembles the Cyrillic я (ya).
If a player does not have Unown's Pokédex data on a Generation II game when in Oak's lab in Pokémon Stadium 2, Unown's Pokédex number is listed as 252 instead of 201. This happens regardless of which Pokédex display mode is selected.
Unown is the only Pokémon with a base stat total of 336.
Unown currently is represented in the Trading Card Game by the most cards of any Pokémon after Pikachu, with 90 unique cards.
The two main official artworks for Unown represent a G-shaped Unown (for Pokémon Gold and Silver Versions) and an F-shaped one (for Pokémon Ruby and Sapphire Versions onward), which may allude to the acronym for Game Freak.
Unown's appearances are corruptions of the modern Latin alphabet, as well as the exclamation mark (!) and the question mark (?), while the G form of Unown is based on a double-story lowercase G. The shapes of the Unown are used like graphic symbols in the Pokémon world, although in Hoenn and the Sevii Islands, their place is taken by Braille. Unown being weak alone and strong together may be inspired by the idea that a single letter can not convey much information, but many letters forming a sentence can communicate a hypothetically infinite number of interpretations and ideas.