- Alternate Character Interpretation: Is Henry a put upon man, a neurotic womanizer, or, indeed, completely insane?
- Non Sequitur Scene: Two major scenes in the movie could either be this or subtle touches of symbolism.
- The twenty or so minutes of deleted scenes from the original print (now lost) were supposedly cut for being too much BLAM...
- Squick: See Nightmare Fuel and add the worms (quite possibly giant sperm) that are everywhere.
- They may symbolize giant sperm, but they are umbilical cords swiped out of a hospital dumpster. One assistant stepped on one accidentally and was so disgusted that she quit the whole production.
- Another interpretation is that the worms are developing foetuses of monster-children much like the baby Henry and Mary already produced.
- Ear Worm: the "Lady in the Radiator" scene. Among other kinds of worm.
- Everyone Is Jesus in Purgatory: Henry's world certainly feels like purgatory.
- Freud Was Right
- Hey, It's That Guy!: Paul is Napoleon Wilson.
- I Am Not Shazam: There is nobody named "Eraserhead" in this movie. Despite what you might think, the title doesn't refer to Henry's haircut, it refers to a scene in the movie where somebody makes pencils out of his severed head. It Makes Just As Much Sense in Context.
- Large Ham: The Manager of the Pencil Factory
- Reptiles Are Abhorrent: If the baby, looking like the love child of a tadpole and the Loch Ness monster, counts.
- True Art Is Incomprehensible
- The Woobie: Henry, briefly, Paul, The Baby.
- Ugly Cute: The baby.
- And the Lady in the Radiator.