About

Dennis is how Pokémon fans may refer to the final boss of Pokémon Black and White, Ghetsis (Japanese: Geechisu, which was the only known name at the time). It is usually elongated and in all-caps, and is often posted on any video regarding Ghetsis' theme or Ghetsis in general.

Origin

On September 18, 2010, Pokémon Black and White were released in Japan. However, the games' soundtracks had already been leaked prior to that release date. Once the games' soundtracks were uploaded to YouTube, those who listened to Ghetsis' battle theme noticed its Latin chanting. It says "Ghetis", although some people misheard that and thought that the voices said "Dennis". This started the phenomenon.

The chanting can be heard in the above video, from 1:32 onward.

Spread

The meme spread around on YouTube, to which people uploaded several videos about the misheard name of Ghetsis. One notable example is a video called "Denis' Final Blow", uploaded on October 20, 2010 by the YouTuber giancarloparimango11, shown below, which has a total number of views of over 400,000 as of now. It shows a Blitzle (back then known as Shimama) called Denis battle a hacked wild Genesect (back then known as Genosekuto), during which Ghetsis' battle theme plays. This caused some confusion of Dennis with that Pokémon, leading to more Dennis videos depicting Genesect being uploaded.

Furthermore, several other thoughts about the chanting have shown up; for instance, some jokingly thought the chanting said "Penance", and there are many variations besides that. Although it was a meme exclusive to YouTube, Dennis has remained notable in the Pokémon fandom outside YouTube as well.

Search Interest

The Google Trends search results graph shows peaks around the release date of Black and White in Japan, and the international release in March 2011.