These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Hell Is That Noise: When Ichabod rides in Sleepy Hollow's forest you can hear the cricket chirping "Ichabod, turn back", an owls hoots "Go, go", a toad croaks "Headless Horseman", the wind blows the reefs and creates a sound like ghastly moaning and a crow caws "Here he comes" and "Beware, beware..."
One student also draws a caricature of Ichabod Crane - and you can see him about to smack the student with a stick (only the sight of the student's overflowing lunch basket stops him). To a viewer who was born after the 1970s, this would seem surprising - though this was standard behaviour for teachers at the time. (Even when it was animated!)