One of the most compelling science fiction characters is found in Frank Herbert's 1962 novel Dune
. The desert planet Dune has the singular feature of being the only world in the known galaxy where one can find the valuable commodity "spice," which permits interstellar travel at greater-than-light speeds. An entire galactic empire has grown up around the spice trade, with planets ruled by dynasties called "houses." Without spice, the entire pyramid of power would collapse. There's a long involved messiah plot, but for our purposes all you need to know is that the House of Atreides ("good guys") and House Harkonnen ("bad guys") are mortal rivals.
The bull-goose bad guy of House Harkonnen is the Baron, Vladimir Harkonnen. In the original novel he's a quintessential '60s-vintage villain: no tormented childhood like Tom Riddle in the Harry Potter
series; no nuanced or redeeming qualities whatever. Herbert also made him both homosexual (or perhaps bisexual, depending on how you interpret the story) and hugely fat. Both qualities were, I believe, picked by the original author to make him more of a "monster."
As it often happens, subsequent versions often re-imagine, re-vamp, and re-vision a sharply-drawn character. Keven MacMillan in David Lynch's 1984 version played the Baron as a pustulent raving lunatic. ( The Baron Harkonnen, with a few NSFW )