In creating Victor Frankenstein and his creature, Shelley developed a literary and psychological archetype known as the Shadow or Doppelganger. This archetype works as an "other self" to the protagonist, mimicking many of the protagonist's characteristics; it is often rendered as an evil twin. In the novel, the creature can be interpreted as Victor's "shadow." In the following excerpt, Victor reacts to the appearance of the creature:
I had selected his features as beautiful. Beautiful! Great God! His yellow skin scarcely covered the work of muscles and arteries beneath; his hair was of a lustrous black and flowing; his teeth of a pearly whiteness; but these luxuriances only formed a more horrid contrast with his watery eyes, that seemed almost of the same colour as the dun-white sockets in which they were set, his shrivelled complexion and straight black lips.
Read in context of the Shadow motif, this passage