Fans were surprised to discover that Mimikyu in the new "Pokemon Sun and Moon" was actually a terrifying creature, instead of a cute and friendly one. Even Meowth in "Pokemon Sun and Moon" was scared of the new Pokemon that dressed just like Pikachu.
Kotaku revealed that when Mimikyu appeared in the new "Pokemon Sun and Moon" anime, he was covered in blue and purple light that appeared much like electricity. Furthermore, the Ghost/Fairy Pokemon looked at if it were holding a grudge. Mimikyu is officially described as a Pokemon that makes itself look like Pikachu because of the growing popularity of Pikachu-styled merchandise about 20 years ago.
GameRant wrote that underneath the Pikachu costume is a mysterious and unidentified Pokemon from "Pokemon Sun and Moon." It was also believed that a researcher who tried to look beneath the costume died from shock.
In December 1997, one episode of the original Pokemon anime series featured children having seizures. Almost 700 kids were hospitalized from what was described as Pokemon Shock. Some "Pokemon Sun and Moon" theories suggest that Porygon, who appeared in the old episode, which was shelved, is actually the secret Pokemon in costume.
"Pokemon Sun and Moon" fans also took some hints that may point to Porygon being the mysterious costumed Pokemon. In "Pokemon Sun and Moon," Mimikyu can be found at the same place where Porygon is situated. Also, Mimikyuseemd to be enraged at the sight of Meowth, hinting that its origins may be linked to Pikachu.
Porygon has not appeared in another episode since the Pokemon Shock incident, presenting that Porygon may still be bitter about Pikachu getting all the sympathy at the time. It may have decided to take after Pikachu, and mimic the beloved Pokemon, which also explains its name.
All the "Pokemon Sun and Moon" theories point to the idea that Mimikyu may actually be a dangerous creature with a grudge. "Pokemon Sun and Moon" are currently available on Nintendo 2DS and 3DS. More updates and details on "Pokemon Sun and Moon" and Mimikyu are expected soon.