Diagnosis: Bananas is a male British Unterganger, better known by his former alias smoglessbutton4, whose YouTube channel was established on 17 September 2011, and his first Downfall parody (Hitler is informed that a train is going to kill him) was uploaded 2 days later.
Diagnosis: Bananas used Windows Movie Maker and, more recently, VideoPad, for video editing, and Picasa 3, GIMP 2 and Adobe Photoshop for picture editing. He often uses audio and visual content from other sources (in addition to the Downfall film footage) in his videos. However, he also makes several parodies using only Downfall footage.
He is a big motorsports fan, and this has often been reflected in his parodies.
- smoglessbutton4's first parody was Hitler is informed that a train is going to kill him. This involved the Hitler is informed/Hitler reviews scene and consisted of Hitler ranting due to the fact that he did not believe what he had just been informed, then a train promptly gets driven into a bunker and blows it up. Trains would not appear again in smoglessbutton4's parodies until Hitler plans to drive a train, which was uploaded almost 7 months later. smoglessbutton4 later 'remastered' his first parody and provided a further explaination into how the train got to the bunker.
- It is later implied that the events of Hitler plans to get out of the space-time paradox have caused Hitler and company to be trapped in a never-ending time loop.
- Hitler was also blown up by a train in Diagnosis: Bananas' 500 subscriber celebratory parody, which has since been made private.
"Hitler's F1 race" series
- Main article: Hitler's F1 Race
- The Hitler's F1 race series are (statistically) the most successful of all Diagnosis: Bananas' parodies. These videos consist of Hitler competing in Formula One races and, like with almost everything he does, failing miserably. Whether it's colliding with a driver he doesn't like or simply getting round the first corner, you can always trust on Hitler to cause some kind of chaos.
First retirement and return
On the 2nd February 2013 he announced that he was retiring for personal reasons, but did not rule out a return.
On 4 April 2013, three days after posting an April Fools joke that stated that he was returning, smoglessbutton4 announced that a return would be forthcoming, and that he was "preparing a few kick-ass parodies ready for a spectacular return", thus confirming his intention to come out of retirement.
He marked his return with a series of parodies and also made it clear that almost all of his future uploads would be Downfall Parodies, though this proved not to be the case.
smoglessbutton4 announced his retirement on the 29th December 2013, mainly due to lack of motivation and other personal issues.  He did, however, state that he would make one final parody, to be uploaded in the near future. Shortly after his retirement, smogless found himself at the center of a heated controversy, after coming across a near-replica of his video Caramelldolfy, later encouraging the use of the term Third-generation Untergangers. Some time afterwards, his YouTube channel underwent a change of name, to Diagnosis: Bananas, and the majority of his parodies were made private.
To date, the 'grand finale' parody has yet to have been uploaded, but D:B has stressed that it will still happen. On 17 May 2014, a preview video, Hitler: The end of the line...? was uploaded to his YouTube channel. However, since the upload there has been no sign of the rest of the movie. However, on 23 July 2015, he claimed on Hitler Rants Parodies' chatroom that the final parody is still happening and that it will be released this summer. He says that the delay was at least partly caused by Videopad, for it "hasn't helped speed things up".
On 20 July 2015, he uploaded a zip file of almost all of his parodies online, calling it "The (almost) complete collection of Diagnosis: Bananas (smoglessbutton4) parodies".