What is Krokodil? It is a homemade drug which is injected straight into the veins, it's 3 times more addictive than heroin which makes it more dangerous.
Among it's components you find gasoline, thinner, ethyl alcohol and acids, this causes the flesh eating effect, leaving it to rot, hence why it is named "Krokodil" making reference to a crocodile, it leaves the skin with a green hue, sometimes purple with scales.
It appeared in Russia, currently it is unknown how long it's been out on the streets, but what is known is that it has made it's way to the United States, to the state of Arizona to be precise.
The state has reported that so far, 2 people have been treated because of this condition. The cost of the drug is 3 times less than Heroin, it produces the same sensations, and it is used in the same way.
However, the lifespan of someone who uses this drug is 3 years at the most, given that because of it's components and effects, the damage done is irreversible.