An episode of The Simpsons called `` Thirty Minutes Over Tokyo '' made fun of `` DennÅ Senshi Porygon '' . It was determined the seizures were caused by watching an episode of PokÃ mon `` DennÅ Senshi Porygon '' , ( most commonly translated `` Electric Soldier Porygon '' , season 1 , episode 38 ) ; as a result , this episode has not been aired since .