Porygon is a Pokémon made completely out of programming code. It has a pink, polyhedral head that ends in a blue beak and has hexagonal eyes and it has a pink polyhedral body with a blue front, blue triangular prism feet, and a blue rectangular prism tail. In 3D games, such as Pokémon Stadium, it can detach its limbs and head from its torso. According to its Pokédex entries, it has copy protection built into its code, preventing duplication through electronic means. It was created 20 years ago at the Pokémon Lab on Cinnabar Island using the latest state-of-the-art technology of its time, so many of its parts have since become obsolete. It was the first artificial Pokémon to have ever been created through computer programming.
Due to its man-made origins, Porygon does not need to breathe or eat, though it can still accept food if given. It has the ability to convert its body into digital data, allowing it to travel through cyberspace. Recently, it has become more helpful inside cyberspace by searching for any suspicious data that exists. Some believed Porygon has the power to potentially travel in space despite the species not displaying that ability yet. Porygon has two signature moves, Conversion and Conversion 2, and in the past it also had Sharpen for a signature move. It can use Conversion to change its appearance to mimic another Pokémon's and has also demonstrated the ability to change color for camouflage. Because it is man-made, it is generally found in computers or in labs and other buildings where people work.
Porygon's only major anime appearance was in EP038. Dr. Akihabara created two specimens, one of which was stolen by Team Rocket, while the other one was borrowed by Ash and his friends. Both remained with Dr. Akihabara at the end of the episode.
This episode caused more than 600 children in Japan to be transferred to hospitals by ambulance because of seizure-like symptoms they reported, due to a flashing strobe effect present at several points of the episode, and was therefore banned and never aired again anywhere in the world. Since then, Porygon and its evolved forms, Porygon2 and Porygon-Z, have never played a main role in the anime.
Porygon pops out of a door on top of the Silph Co. building in the Saffron City stage. It damages players that come into contact with it.
Porygon's only appearance in Melee is that of a Poké Float. When the fighting is on Slowpoke's tail, three will travel across the top of the screen. However, they move too quickly to land on and so are little more than decoration in practice.
Porygon is the only Pokémon that evolves by trade twice: once holding the Upgrade into Porygon2, and a second time (as Porygon2) into Porygon-Z when holding a Dubious Disc. It is also the only Pokémon in a three-stage evolutionary line that does not require leveling up to trigger any of its evolutions (i.e. it is possible to acquire a Porygon-Z at level 1).
Porygon's evolutionary line is the only three-stage evolutionary line whose members were considered fully-evolved during their respective debut generations.