I don't really think this counts as imagery, but i love it anyways. It's from House of Leaves, by Mark Z. Danielewski. If you haven't read it, go get it now. It is scary, interesting, completely insane, experimental, and a ridiculously good read. Anyways, here ya go:
To get a better idea try this: focus on these words, and whatever you do don't let your eyes wander past the perimeter of this page. Now imagine just beyond your peripheral vision, maybe behind you, maybe to the side of you, maybe even in front of you, but right where you can't see it, something is quietly closing in on you, so quiet in fact you can only hear it as silence. Find those pockets without sound. That's where it is. Right at this moment. But don't look. Keep your eyes here. Now take a deep breath. Go ahead, take an even deeper one. Only this time as you exhale try to imagine how fast it will happen, how hard it's gonna hit you, how many times it will stab your jugular with its teeth or are they nails?, don't worry, that particular detail doesn't matter, because before you have time to process that you should be moving, you should be running, you should at the very least be flinging up your arms-you sure as hell should be getting rid of this book-you won't have time to even scream.
Of course I looked.
I looked so fucking fast I should of ended up wearing one of those neck braces for whiplash.
I sing anyway.