AttackConversion 1
If the Defending Pokémon has a Weakness, you may change it to a type of your choice other than Colorless.

Porygon is Pokédex #137, generation 1 (Kanto). Porygon is a Basic Colorless Pokémon with 30 HP. The card lists level 12. The card lists Porygon2, Porygon2 (#233) under evolves to.
Porygon sits at 39/102 in Base, position 39 of 102. Before it is 38 Poliwhirl, and after it is 40 Raticate. The set belongs to the Base series. It was released on 9 January 1999. The printed size is 102, and the checklist is the same length. The listed rarity is Uncommon.
The attack Conversion 1 lists no damage number. The cost is Colorless. If the Defending Pokémon has a Weakness, you may change it to a type of your choice other than Colorless. Conversion 2 is another attack lists no damage number. The cost is Colorless, Colorless. Change Porygon's Resistance to a type of your choice other than Colorless. Weakness is Fighting ×2. Resistance is Psychic -30. Retreat cost is 1. The flavor text reads "A Pokémon that consists entirely of programming code. Capable of moving freely in cyberspace."
Porygon (#137) has 23 other cards in the catalog. Those other cards are in 22 sets. The other printings with a release date run from 1999 to 2025. The earliest other card is Cool Porygon 15/53 in Wizards Black Star Promos (1999). That card is named Cool Porygon, while this one is Porygon. That card lists 50 HP, and this one lists 30 HP. The rarity there is Promo, and here it is Uncommon. Hiromichi Sugiyama illustrated that card, and Tomoaki Imakuni illustrated this one. 23 other cards of Porygon list a different HP.
The illustrator line reads Tomoaki Imakuni. I count 13 other cards in the catalog with that illustrator.
Base set binder is where a full Base set goes. This card fills one slot there. A generation binder holds one card of each species. Porygon can fill a slot in Generation 1 binder (Kanto). I still need this card.
If the Defending Pokémon has a Weakness, you may change it to a type of your choice other than Colorless.
Change Porygon's Resistance to a type of your choice other than Colorless.
A Pokémon that consists entirely of programming code. Capable of moving freely in cyberspace.
Base, in the Base series. It was released on 9 January 1999. The printed size is 102.
39/102. It is entry 39 of 102 in this checklist.
Tomoaki Imakuni. The catalog lists 13 other cards with that illustrator.
Uncommon.
Porygon #137, generation 1 (Kanto).
Conversion 1 and Conversion 2.