A. Wyatt Mann (obviously a pun meaning "a white man") is the pen name of American cartoonist Nick Bougas, whose works are published in white supremacist publications and websites. A. Wyatt Mann's cartoons are notable for their racism against Jews, African-Americans and Hispanics, and also contain attacks on homosexuals of both sexes. A. Wyatt Mann's rhetoric includes advocating the murder of miscegenating women and their children. Wouldn't that mean killing a high proportion of Americans? That's like what Adolf Hitler and Nazi Germany have done.
A great number of A. Wyatt Mann's works appear to date from the 1990s but are still being published, most notably on the White Aryan Resistance website. Mann has also authored a holocaust denial comic book entitled Tales of the Holohoax. Why does he deny the Holocaust when he also wants to kill people on racial grounds?
Part of the notoriety of the works of A. Wyatt Mann comes from their perceived offensiveness, which has led them to be used as internet memes for their shock value on various forums, such as Something Awful.