Porygon after spending time with Red
Porygon2 first appeared as a Porygon in A Tale of Ninetales, when Blue bought it from the Rocket Game Corner. After Blue let Porygon out of its Poké Ball, it ran away, causing Blue to run into Red. Because of this, the two accidentally trade their Pokémon. During the three days that Red has Blue's team, he attempts to get them to relax and open up to him, with little success. They later traded back, while keeping the caring attitude that Red instilled in them.
In The Art of Articuno, Porygon and Pika successfully surprise attack Koga and knock him out.
As revealed in Entranced by Entei, Porygon was used by Blue at some point during the Pokémon League.
In The Primeape Directive, Porygon helped to defeat a group of rampaging Mankey and Primeape after using its ability to move through cyberspace to switch from Blue's Pokédex to Yellow's.
In Striking Golduck, Porygon was Blue's last resort to fight Agatha's Gengar. Because Gengar would hide in the shadows and attack with Counter, Blue decided to use Porygon's Conversion to turn into a Ghost-type. Porygon was then able to counter Gengar's Counter attack but was unable to get Gengar out of the shadows long enough to land a finishing attack. Blue eventually managed to lure Gengar out of the shadows and had Porygon finish it with Psybeam.
In Playful Porygon2, Porygon was revealed to have evolved into a Porygon2. It fought against Silver's Sneasel before they were interrupted by Entei.
Porygon2 traveling through cyberspace
In Red and Blue Make Purple Opponents, Porygon2 is used alongside Golduck in a Double Battle against Red and his Snorlax, Snor and his Gyarados, Gyara. Gyara starts the battle off with his Intimidate Ability, to which Blue responds by having Golduck use Iron Tail and Porygon2 use Tri Attack on Red's Pokémon. Red then has Gyara counterattack by Body Slamming Porygon2, while Snor attacks Golduck with Strength. Gyara next uses Hyper Beam on Golduck, and Golduck uses Dig to hide and avoid further damage. Red counters by having Snor use Earthquake, dealing damage to Porygon2, twice the damage to Golduck due to him being underground, which causes him to faint, and Gyara being unaffected. due to him being part Flying-type. As Red celebrates. he notices that Gyara had been paralyzed by the effects of Tri Attack. Blue takes the opportunity to switch Porygon2 out in favor of Scizor.
In Once More into the Unown, Porygon2 uses its ability to move through cyberspace to enter into the Trainer Tower's computer system, "R". Using the Salac Berry that Blue gave it, Porygon2 quickly reaches the central nervous system and attacks with Zap Cannon, disabling it. Not long after this, "R" recovers and traps Porygon2 with a virtual lock.
In The Final Battle VII, Porygon2 battled Guile Hideout's stolen Battle Tower Pokémon.