What is the name of the new street drug that rots your flesh and can be fatal?
You may be referring to Krokodil, the flesh-eating drug which originated in Russia in 2002. In the United States, it was originally reported to have been found in Utah and Arizona in 2013. So, yes, it's a fairly new drug.
Krokodil is the nickname for desomorphine. It can be made at home by cooking up codeine (an over-the-counter drug for headaches) with paint thinner, hydrochloric acid, gasoline, and other corrosive ingredients. Krokodil is more toxic than morphine and more addictive than heroin. For someone going through withdrawal from Krokodil, he/she can expect to endure excruciating physical pain for at least a month. For those who are fortunate enough to walk away from the drug, many scars will remain; former addicts may have to contend with speech impairment issues, mild to severe brain damage, motor skill impairment issues, and limb loss.
Krokodil is so named because it causes the skin of addicts to become inflamed, scaly, and green in color. Because Krokodil is supposed to be injected into veins, any accidental injection into the flesh itself can lead to necrosis, the death of skin tissue. Often, the skin rots off completely, and you can see bare bones as a result of the rot. It's a very dangerous drug!
For more, please refer to my sources below.