MrTNeumann was an Unterganger who based his parodies in a more traditional style of basic subtitles.
During the mid-2010 DMCA crisis, he created an alternative account known as FuckYouHRP, a channel directed against Hitler Rants Parodies for criticizing his overall influence during the removal of most other parodies through the DMCA. Upon the suspension of his mainstream account, FuckYouHRP was subsequently deleted afterwards. The current status of MrTNeumann is unknown.
Two of his videos still exist, saved by LostDownfallParodies.
Other potential suspects
Since nobody has conclusively proved that MrTNeumann was behind the offensive channel, speculation has risen that the actual creator of the channel could be someone else. Nietzscheprime and others have speculated to this effect - believing that another (such as Shomronon) could also be guilty of founding the abusive channel, taking into account the fact that the former had resented HRP for some time, and opposed his influence within the community.