New life form living in sewers?

Yeah, I know it is the question horrible B-movies are based on... but check this out.. What is that? Never seen anything like it before... and notice the 3rd one they film, it has an odd protrusion it retracts back into itself. I was hungry before running across this clip.... That looks very weird! I wonder what it is... Source: http://www.youtube.com.../

Just maybe it's an extraterrestrial - if you don't believe read "Dreamcatcher" by Stephen King