Cannibalistic Humanoid Underground Dwellers for the win, please...
C.H.U.D. is a 1984 American horror film produced by Andrew Bonime, and directed by Douglas Cheek with Peter Stein as the director of photography and William Bilowit as production designer.
The cast includes Daniel Stern and John Heard and features early appearances by both John Goodman and Jay Thomas as police officers.
It was followed in 1989 by C.H.U.D. II: Bud the C.H.U.D.