This was distributed in the United States as part of a pre-packaged double feature with Beginning of the End (1957).
Completed in six days by at least May 1957.
Actor Arthur Batanides stated that he believed that the house where they shot this feature once belonged to Mary Astor.
The Lobo character here (who can speak) was created by writers Mann and Black. He is a different character than the mute Lobo created by Ed Wood Jr. in "Bride of the Monster" and "Night of the Ghouls". Screenwriter Jane Mann was the wife of director Boris Petroff.
Despite the title, the plot of "The Unearthly" contains no extraterrestrial element.