The Naga Viper (capsicum chinense) has been rated at 1,382,118 Scoville Heat Units (SHU), according to tests conducted by the Warwick HRI Mineral Analysis Laboratory, UK, in November 2010. The Naga Viper chili pepper is a hybrid of three different chili peppers - the Bhut Jolokia, the Naga Morich, and the Trinidad Scorpion. It was created by Gerald Fowler, who runs the Chili Pepper Company in Cumbria, England. This pepper is hotter than the Naga Jolokia (or Bhut Jolokia) by a scorching 300,000 Scovilles, and is claimed to be able to peel paint. In comparison, pure capsaicin is rated at between 15,000,000 - 16,000,000 Scoville units, and police grade pepper spray is rated at about 5,000,000 Scovilles.
This blistering pepper was reportedly grown in a greenhouse during wintry weather, as opposed to the oven-like heat of the Indian or Mexican climates.
Note: "Naga" mean "Cobra Snake" in Sanskrit.
Please note that while the Guinness Book of World Records reports this as the hottest chili pepper in the world, there is dispute and it is not officially recognized by the Chile Pepper Institute in New Mexico.