X-rays are incredibly useful medical tools, but they don't have to just be for doctors. They also make for cool works of art.
While the x-ray's primary use is to find broken bones or other ailments, they can give you a rare and fascinating glimpse at the wonders of the human body. In this case, they make for fantastic GIFs.
See also: Look at These 10 GIFs and You Might Actually Learn Something
Take a look at what's moving around under your skin — it's enough to make yours crawl.

Image: Wikimedia Commons/Ruhrfisch