I was living in the Philippines in 1976 and my family’s house girl was watching the tv and I remember a reveal of a baby that was actually a demon.  It scared the shit out of me for years.  I vaguely recall that it may have been by the tall grasses along a river.  The movie could have been American, but was most likely not, possibly Filipino or from somewhere else in southeast Asia.  Sorry to be so vague.  It was a long time ago.  Does this ring a bell for anyone?