Shortly after Nintendo revealed the newest Pokémon, Pocket Monsters X/Y, the above image started circulating on Twitter. "This seems to be an image of the evolved Pikachu from the new Pokémon," the tweet read.
Another image of this evolved Pikachu, which was apparently named "Kaenchu" (カエンチュ), also started making its way around the internet in Japan around the same time. The name "Kaenchu" contains "kaen" (火炎), the Japanese word for "flame" or "blaze".
Kaenchu is supposedly able to generate thermal power and unload hydrogen explosions. On Twitter, people started writing how cute the character was, and the word "Kaenchu" began trending on Yahoo! Japan, hitting number four. The tweets of the "leaked images" were retweeted several thousand times.
Pokémon players know that there is already an evolved form for Pikachu, dubbed "Raichu"—a form that Ash's Pikachu doesn't evolve into.
So, an evolved Pikachu that isn't Raichu? Thermal power and hydrogen bombs? That art? Japanese site Nari Nari points out that, yes, this is the work of Japanese bulletin board 2ch, where the character originated. Some folks on 2ch, it seems, aimed to troll Twitter users, who "stupidly" forward tweets—tweets that now, Nari Nari adds, Japanese Twitter users are deleting.
偽ポケモン「カエンチュ」拡散、設定や絵を2ちゃんねる有志が創作。 [ナリナリ via DSPSP初心者講座]