C.H.U.D. (1984) [Uncut Version] Toxic Waste Mutants Mangle & Terrorize New Yorkers

"Cannibalistic Humanoid Underground Dwellers"
or "Contamination Hazard Urban Disposal"
Starring: John Heard (Home Alone) and Daniel Stern (Home Alone)
and a very brief bit-part by John Goodman as a cop in a diner.
A VERY awful sequel was made to this called "CHUD II: Bud the Chud", avoid at all cost.
Plot:
A rash of bizarre murders in New York City seems to point to a group of grotesquely deformed vagrants living in the sewers. A courageous policeman, a photo journalist and his girlfriend, and a nutty bum, who seems to know a lot about the creatures, band together to try and determine what the creatures are and how to stop them.