* BrokenBase: On whether the inclusion of the demon adds or detracts from the film.
* SpecialEffectFailure: The closeups of the demon are more likely to inspire laughter than terror. Other effects, however, are really pretty good.
** The closeups were a result of ExecutiveMeddling - director Creator/JacquesTourneur wanted the demon to be barely glimpsed. The demon's smoky long shots are effective, though.
** A failure everyone can agree on is the scene where Karswell's cat Graymalkin turns into a leopard and attacks Holden-- Dana Andrew's pretty obviously wrestling with a taxidermy model.
** When Karswell leaves the train to chase the parchment with the runes, you can clearly see the wire on which it's hanging.
* VisualEffectsOfAwesome: The demon looks very impressive for the 50's.
** For that matter, the scenes where we don't see the demon but rather the effect it's having on the world, like the smoking hoofprints in the forest being left by [[NothingIsScarier something we can't even see]], are VERY effective.
* WatchItForTheMeme: A lot of Music/KateBush fans found out about this film through her song [[http://www.youtube.com/watch?v=VerK4zwMRQw Hounds of Love]], which opens with the sampled line "It's in the trees, it's coming!"