Porygon

Overview

Porygon was the first artificial Pokemon ever created by Pokemon Lab , according to information found in Silph Co in the original three Pokemon games. They have since appeared in every Pokemon release and can be found in Pal Park. Porygon are made entirely of programming code and have embedded copyright protection to prevent electronic copying. They can travel freely through cyberspace by reverting themselves to pure code and, although none have done so, scientists believe they can travel through space. Because they are completely artificial and man-made, Porygon are extremely rare in the wild and are generally found in labs and computers. However, they can be found in the Trophy Garden in the Sinnoh Region and are offered as the highest prize in Rocket Game Corner.
 
Although Porygon are completely artificial, and do not need to eat or breathe, they can be seen eating in Pokemon Snap and the Mystery Dungeon series. They can also be fed or be seen eating Poffins in Pokemon Diamond, Pearl and Platinum. Porygon can be evolved into a Porygon2 when traded holding an Up-Grade, or into a Porygon-Z while holding a Dubious Disk. They can detach their head and limbs at will and are continually floating. They can also turn transparent. Despite being developed by humans and generally created by computers, a Porygon can be hatched from an egg.
 
Porygon are infamously absent from the Pokemon anime series. It is most likely that this is because their anime debut, "Electric Soldier Porygon", was banned worldwide for causing almost 700 children to have epileptic fits due to a rapidly flashing attack effect. Although the attack that caused the seizures was actually Pikachu's Thunderbolt attack, Porygon has not been seen in an episode of Pokemon since, besides a single 'Who's That Pokemon?' appearance.

Data

National Pokedex No: #137
Type: Normal 
Ability: Trace/Download

Evolution
Porygon does not evolve in the 1st generation.
It evolves in 2nd generation to Porygon2 when traded while holding an UpGrade item.
In the 4th Generation,  Porygon2 can evolve into Porygon-Z when traded  while holding  the Dubious Disc item.