Merg

Merg (or MyEveryRottenGiggles) is a Geometry Dash YouTuber/commentator with almost 74,000 subscribers as of 12/28/2016. He has beaten demons such as Nine Circles, Windy Landscape, The Furious, and Fairydust.

Description
While Geometry Dash is the main series on his channel, he also plays other games. One of the biggest series on his channel (aside from Geometry Dash) is Undertale which has one of his most popular videos. He has finished the 2 main routes of Undertale but he plays fan games.

Trivia

 * He is friends with EricVanWilderman, and the two often comment on each other's YouTube videos.
 * Merg has said that he will start making his own demon levels when 2.1 releases.