Heigh Ho is the name of the song from Snow White And The Seven Dwarfs (1937).
In the movie, Gremlins (1984), at the Kingston Falls Movie Theatre, the gremlins watching "Snow White". And as the seven dwarfs sing "Heigh Ho", the gremlins can sing, too. At the snack stand, Gizmo (with Billy and Kate) hears and sings the song. At the end of the movie, "Gremlins", as Mr. Wing takes Gizmo back home, he (inside of the ancient box) sings the same song from "Snow White".