Superman and the Mole-Men (1951)

Reporters Clark Kent and Lois Lane arrive in the small town of Silsby to witness the drilling of the world's deepest oil well. The drill, however, has penetrated the underground home of a race of small, furry people who then come to the surface at night to look around. The fact that they glow in the dark scares the townfolk, who form a mob, led by the vicious Luke Benson, intent on killing the strange people. Only Superman has a chance to prevent this tragedy.