No, this doesn't come from a mythical creature. Dragon blood is the name given for an intensely red tree sap which oozes from the Croton lechleri tree when its trunk has been cut or injured. It's native to the northwestern part of South America, primarily Columbia, Ecuador, Peru, and Bolivia. It grows at an astonishingly fast rate, up to 1 foot per month under the right conditions, reaching a mature height of up to 60 feet (source: PDF).
The dragon blood, which is known as Sangre de Grado in Peruvian Spanish, has reportedly been used for hundreds of years as an alleged herbal remedy for skin wounds, diarrhea, and other ailments.
Give its ORAC value you may assume it's a superfood and indeed, many people use it as a dietary supplement. Though it is worth mentioning there is conflicting research out there as to whether or not it might have a side effect of being a mutagen.
A study from 2003 found it had no mutagenic activity when tested against Salmonella typhimurium strains T98 and T100 in the lab (1).
However a year later in 2004, another study found mutagenic activity when it was tested against two Salmonella typhimurium strains; TA98 and TA1535. One strain of Saccharomyces cerevisiae (XV185-14c) also showed the same (2).
It took almost a decade, not until 2013, when another paper was published on this topic. Rather than finding it to be a mutagen, they touted the opposite, that it was a "possible mutagen-protective food ingredient" (3). That would be a good thing, if it ends up being true. Three studies aren't enough, a lot more research should be done to get to the bottom of this. Perhaps sticking with astaxanthin, which has almost the same ORAC value, would be a better idea. photo credit: "Sangre de Grado, Croton lechleri" by Por Natikka via Wikimedia Commons (CC by 2.5)
Research Support, Non-U.S. Gov't: Carlsen MH, Halvorsen BL, Holte K, et al. Nutrition Journal NIH Jan 2010