Book excerpt: This dissertation defines and explores the concept of superhero monstrosity through an analysis of the character Superman, the television series italicSmallvilleitalic, and several other post-2000 superhero films and television shows. 0́Monstrosity0́+ is my term for the superhero's corruption by internal or external forces that overturn his role as a protector and reveal the anxieties at the heart of the genre. The genre foundationally counteracts anxieties regarding the corruption of the powerful and the impotence of the average person by creating superhuman figures who protect the weak, seem incorruptible, and allow the audience to experience power vicariously. However, these anxieties constantly reappear in the form of stories featuring monstrous superheroes. I do a historical overview of the genre to show that, though monstrosity is a component from the beginning, it does not become a central aspect until after 1960 in comic books and 2000 in film and television. Most of the dissertation is focused on the television series italicSmallvilleitalic because it embodies the post-2000 shift to monstrous superheroes in mainstream media, as even Superman, the first and most unchanging superhero, struggles with destructive tendencies. Specifically, I look at how the program's pre-Superman Clark Kent goes through a super form of puberty that results in him repeatedly losing control of his body and exhibiting potential to grow into a villain. Moreover, I analyze cases in which the superhero turns into a completely immoral monster (a 0́superhero-gone-bad0́+) on italicSmallvilleitalicand in several superhero films. These totally corrupted superheroes engage the genre's anxieties and fantasies in an exaggerated way. In proving my argument, I do close analysis of formal and narrative elements of various episodes of italicSmallvilleitalic, as well as several other films, TV shows, and comic books. In addition, I look at fan reactions (primarily on the internet) to gauge what makes monstrous superheroes appealing and frightening, and what a successful depiction demands. In the end, what I hope to show is how changes in cultural sensibilities and the superhero genre result in renditions of protagonists who are both heroes and destroyers on Smallville and in other post-2000 films and TV shows.