Eraserhead is well known for being enigmatic and creepy. It’s a story of a loser everyman in a bizarre setting who experiences strange visions while fathering an even stranger child that doesn’t look remotely human. But it’s what you might expect from David Lynch if you’ve heard anything about him and much milder than you’d expect after you hear the sorts of things he was up to behind the scenes.
For example, he refused to talk about how the effect of the baby was done decades afterward, nor did he allow others to talk about it. Given the appearance of the object, the budget, the skin textures, and the fact it’s so articulated that its eyes will close vertically, the leading theory is that it’s a preserved calf fetus. (Source)