Actually that's pretty awesomely done.

His headworms aren't the kind of thing that has any general shape. In fact, the name headworms is the only they can be called practically because that's the only thing they closely look like.

It's almost like when of those lightning lamps, only that the lightning is dark instead of neon light and they sometimes have mouths. There really isn't anything other then headworms that we can call one of Grey's more interesting hallucination.

But they don't always signify that Grey's mental health is at a good level when they start to appear in force and start eating his skin.

so cool. and utterly terrifying.