Pokémon Gold and Silver introduced 26 letter-based forms of Unown.
The forms correspond to the 26 letters of the English alphabet, giving Unown an unusual visual identity among early Pokémon. In the games, Unown are found in the Ruins of Alph in Johto, where players solve stone puzzles to open access to different forms.
Unown became associated with puzzles, ancient writing, and hidden messages. Their appearance and behavior helped establish the Ruins of Alph as one of Gold and Silver’s most distinctive optional areas. The games encourage players to collect the different alphabet forms rather than treating Unown as a conventional powerhouse.
Later games expanded the total number of Unown forms to 28 by adding question-mark and exclamation-mark variants. That later total is a common source of confusion, but Gold and Silver originally featured only the 26 alphabet forms.