Evil Makes You Hideous is a term used often to describe a phenomena in which a character not only corrupted on the inside due to outside malevolent force or turning to the dark side, but also on the outside where the more he/she become evil, the more hideous he/she become as well.
Like He Who Hunts Monsters, the term of a character whom appearance become hideous as result of commiting more evil acts or willingness to be corrupted by external malevolent force has been populared by TV Tropes in form of two pages, Evil Makes You Ugly (where the character simply had repulsive appearance) and Evil Makes You Monstrous (the character's deformation not just on appearance, but also have personality that warped as worse as the appearance), but did not originate on that website. The term actually originated from various folklores, legends, and myths in real life about horrific consequences should one commit a horrible crime/evil act, often as punishment of their actions. For instance, in Native American mythology, legends about cannibalistic monster named Wendigo is the warning about act of cannibalism, where should one performed act of cannibalism, the said person would turned into another Wendigo as well.
In many stories, heroes may warned by his parents/friends about horrific consequence of literally turned into monstrous creatures as punishment of specific crime or other evil acts.
Marvel Cinematic Universe
- Red Skull: According to Erskine, why Red Skull become extremely evil and having deformed face is clarified due to imperfect Super Soldier Serum revealed the very monstrous side of him: Before his disfigurement, Red Skull already have negative qualities and power hungry traits to begin with, opposed to Steve Rogers aka. Captain America whom only gained super strength but retained his good qualities since he already good guy from start.
- Practitioners of Dark Side of the Force: Practicioners of Dark Side of the Force such as Palpatine would suffer deformation the longer they embrace the Dark Side, where the said deformation started from simply have yellowish eyes. But from there, it could get worse where the skin would become pale and fill of wrinkles, though this not always the case.
Anime and Manga
- Apostles: Apostles are said to be humans who have sacrificed their humanity, dreams, and loved ones to turned into monstrous demons with a Behelit.
- Barraki: The Barraki were turned into their monstrous forms when they fall into the ocean, which was happened to have mutagen due to Kanohi Ignika's power.
- Umarak the Hunter: To begin with, Umarak was already evil and selfish as he not truly loyal to Makuta as he followed the latter for convenience only. That is until dons Mask of Control where his evil nature grows, resulting him also become more like a hideous monster.
- Blight: Even prior to his mutation into Blight, Derek Powers already evil from start. He killed his own employee Harry Tully in cold blood to test his invented nerve gas and later, murdered McGinnis who learned about the gas and make it appear the latter was the victim of The Jokerz gang. Even so, he failed and made McGinnis' son, Terry, who learned about his corrupt ideal with help of elderly Bruce Wayne, becoming a new Batman and stopped his evil plan to sell the gas. However, in ensuing fight, Derek wind up exposed by his very created gas and to make matter worse, radiation treatment that meant to save Derek's life mutate him into monstrous creature with glowing transparent flesh and black skeleton.
Live Action Film
- Jason Vorhooes: Being supernaturally enhanced to monstrous killer that can resurrect himself via electrocution, each demise and resurrection that Jason had, combined with his persistence to kill more victims resulting him stronger and monstrous over time. A testament of his evolution into more hideous killing machine was after blown into bits, his strong drive to kill more people somehow made him returned as parasitic worm zombie after only his heart that survive destruction of most of his body parts.
- Freddy Krueger: Thanks to his deal with nightmare demons, the restless spirit of the child killer Freddy Krueger, whom evil from start, ascends into an undead dream-dwelling human monster.
- Chucky: As a killer doll, he started off as cute looking doll, but it is obvious that due to his bloodlust and evil personality, the look of his doll form become more hideous due to his doll vessel slowly mutating from plastic to actual flesh and blood
- The Evil Queen: For wanting to be the fairest in the land by killing her stepdaughter, when the Queen decides to take matters into her own hands, she first concocts a potion that transforms herself into a hideous old Witch and spends the rest of the movie in that disguise.
- Demons (Supernatural): It was clarified that demons started off as damned souls who corrupted through extensive torture in hell.
- Sorceress Power wielders: It was said that anyone who inherited the Sorceress Power would have physical change which reflect on their personality traits: Had they become evil, their Sorceress power would resulting them taking more monstrous appearance. If they remained good, their physical change will not make them hideous.
- Judge Death: Judge Death, Judge Dredd's undead nemesis, was already evil and sadistic due to sadism that his father taught to him. Death spent his whole life killing people before allowing a pair of witches to turn him and his three lieutenants into undead abominations to achieve immortality. Since he was already pure evil long before his transformation, casting off the last of his humanity means the outside simply started to reflect the inside.
- Lord Voldemort: Harry's encounter with partially corporeal form of a piece of Voldemort's soul that come from his diary and later revelation by Dumbledore about the Dark Lord's past revealed that Voldemort used to be very handsome, but his meddling with dark arts began to deformed his looks that, upon his rising to power that schemed through manipulating Triwizard Tournament, his restored form looked more like a horrifying humanoid creature with snake-like nose and skull-like face compared to his former appearance.
- Mr. Hyde: Due to Mr. Hyde being dark aspect of Dr. Jekyll's psyche given form where the doctor would take hideous appearance whenever Mr. Hyde takes control, it's not surprising that Mr. Hyde emerges as monstrous creature.
- Gollum: After he killed his own friend, Deagol, to get the One Ring, over time, it transformed him into an ugly Hobbit creature.