Hello all, I have a request to know what the name of certain late 70s/early 80s horror movie is called. The plot evolves around some kind of monster hiding in the sewer in the city. It comes out at night, and kills people using its tongue (?). One scene I remember is when two workers doing some checkup-work in the sewer, when one of them is suddenly attacked. The other ones escapes, pushes the lid back on and thinks he's home safe. All of a sudden, the lid is smashed open and the guy is dragged down into the sewer.

This was a REALLY scary one for me in my younger years, and it would be great knowing what the name of it is. I've got a few suggestions that it was "chud", but that's not the one....

Thanks in advance!