Oh! No mortal could support the horror of that countenance. A mummy again endued with animation could not be so hideous as that wretch. I had gazed on him while unfinished; he was ugly then, but when those muscles and joints were rendered capable of motion, it became a thing such as even Dante could not have conceived.

– Mary Shelley

Frankenstein, Chapter 5. Shortly after bringing his creation to life, the weight of what he has done descends on Victor. He describes his creation as hideous.