Mutagens, agents that change the genetic material of an organism and increase the frequency of mutations above the natural background level, are a popular plot device in science fiction and video games, although they are often not accurately represented. Mutations have more often a destructive character than actually "improving" an organism, which usually means augmenting an organism's fitness. This is a list of creative works where a mutagen is featured. Where a work is represented in more than one genre, it is listed in the genre where it first appeared.