Héctor Germán Oesterheld, also known as his common abbreviation HGO (born July 23, 1919; disappeared and presumed dead 1977), was an Argentine journalist and writer of graphic novels and comics. He has come to be celebrated as a master in his field and as one of the pioneering artists in Argentine modern comics. Over the years, Oesterheld's legacy has become vast, influencing several generations of new artists, particularly in literature and comic books.