"This small gesture is for the millions, perv... FOR THE MILLIONS!"
— Future Raphael, Dreamland, Part 3
Adolf Hitler (often misspelled in the story as "Adolph") was a real-world Austrian-born German politician and the leader of the National Socialist German Workers Party (German: Nationalsozialistische Deutsche Arbeiterpartei (NSDAP), commonly referred to as the Nazi Party). He was Chancellor of Germany from January 1933 to April 1945, and head of state (as Führer und Reichskanzler) from August 1934 to April 1945. He is most commonly associated with the rise of fascism and national socialism in Germany and Austria, as well as World War II and The Holocaust.
When the Turtles go to leave, Hitler draws a gun on them. Future Leonardo convinces Hitler that they are demons, and that he is in Hell; since they already have his soul, they've come for his brain. Hitler puts his gun to his head, claiming that they will not take his brain, and pulls the trigger.
↑Dreamland, Part 3(English). Mirage Studios (January 1995). Retrieved on October 26, 2019.