Whip the monsters in a dark alley of death!
This is a scary game - monsters and zombies are attacking you in a dark alley, make sure you whip them to death before they reach you, otherwise, you would turn into a zombie yourself!
Frankenstein by Mary Shelley, while not a zombie novel in particular, prefigures many 20th-century ideas about zombies in that the resurrection of the dead is portrayed as a scientific process rather than a mystical one, and that the resurrected dead are degraded and more violent than their living selves. Frankenstein, published in 1818, has its roots in European folklore, whose tales of vengeful dead also informed the evolution of the modern conception of the vampire. Later notable 19th-century stories about the avenging undead included Ambrose Bierce's "The Death of Halpin Frayser", and various Gothic Romanticism tales by Edgar Allan Poe. Though their works could not be properly considered zombie fiction, the supernatural tales of Bierce and Poe would prove influential on later writers such as H. P. Lovecraft, by Lovecraft's own admission.
In the 1920s and early 1930s, the American horror author H. P. Lovecraft wrote several novellae that explored the undead theme. "Cool Air", "In the Vault", and "The Outsider" all deal with the undead, but Lovecraft's Herbert West–Reanimator (1921) "helped define zombies in popular culture". This series of short stories featured Herbert West, a mad scientist who attempts to revive human corpses with mixed results. Notably, the resurrected dead are uncontrollable, mostly mute, primitive and extremely violent; though they are not referred to as zombies, their portrayal was prescient, anticipating the modern conception of zombies by several decades. Edgar Rice Burroughs similarly depicted animated corpses in the second book of his Venus series, again without ever using the terms "zombie" or "undead".
Avenging zombies would feature prominently in the early 1950s EC Comics, which George A. Romero would later claim as an influence. The comics, including Tales from the Crypt, Vault of Horror and Weird Science, featured avenging undead in the Gothic tradition quite regularly, including adaptations of Lovecraft's stories, which included "In the Vault", "Cool Air" and Herbert West–Reanimator.
Richard Matheson's 1954 novel I Am Legend, although classified as a vampire story would nonetheless have definitive impact on the zombie genre by way of George A. Romero. The novel and its 1964 film adaptation, The Last Man on Earth, which concern a lone human survivor waging war against a world of vampires, would by Romero's own admission greatly influence his 1968 low-budget film Night of the Living Dead; a work that would prove to be more influential on the concept of zombies than any literary or cinematic work before it.