Fun fact: Most zombies got black blood on account of their advanced decomposition and the lack of oxygen in their cells. I mean, that would be a fun fact if they weren't completely made up, but it makes a lot of sense. Why would zombies have live, vivacious, red blood pumping out of their wounds? Why would they still look human? Doesn't hold water with me. That's why we've got the Zombie Black Blood Caps for making your zombie costume look that much more supernatural this Halloween.
Plus, if you don't want to go as a zombie, you can always use the Zombie Black Blood Caps to go as the Black Oil from The X-Files (man, that show used to be awesome).